Tag: Freshwater

Cichlid Tank Mates: My Guide to What Actually Works After 25 Years
I’ve kept Mbunas alongside tiger barbs, rainbow sharks, and pictus catfish. and made it work. But that required a properly sized tank, deliberate stocking order, and plenty of territory. Cichlid tank mates aren’t something you pick at random; success comes down to space, water parameters, and knowing your specific cichlid’s temperament. In this guide I break down the best tank mate options for African, Central American, and South American cichlids based on real experience.
Key Takeaways
- Contrary to popular belief, cichlids can have tank mates!
- There are three main types of cichlid: African cichlids, Central American cichlids, and South American cichlids.
- Aggression varies from species to species and tank mate pairings will greatly depend upon compatibility with other fish, along with water parameters and tank setup.
- African cichlids have the least flexibility in terms of tank mates while South American species have some of the greatest.
Understanding What Type You Have

First, you need to determine what type of cichlid you have. All cichlids are capable of being aggressive, but some can be kept in community tank setups while others can only be kept with members of their own kind.

Luckily, most aquarium stores accurately name their cichlids so you don’t need to wonder what kind you’re taking home. Here are some of the most common cichlids you’ll find.

African Cichlids

African cichlids mainly originate from two freshwater lakes in Africa: Lake Malawi¹ and Lake Tanganyika. Lake Malawi cichlids, including Mbuna cichlids, tend to be more colorful but more aggressive than Lake Tanganyika species.

Lake Malawi cichlids include:
- Electric yellow cichlid (Labidochromis caeruleus). These fish grow to 5-7 inches and are bright yellow with black-trimmed fins.
- Demasoni cichlid (Pseudotropheus demasoni). Demasoni cichlids reach mature sizes between 3-5 inches and thrive in groups. They have alternating black and blue stripes.
- Aulonocara spp. Commonly known as the Lake Malawi peacock cichlids, members of the Aulonocara genus come in reds, blues, and yellows, and grow to about 4-6 inches.
Lake Tanganyika cichlids include:
- Frontosa (Cyphotilapia frontosa). Frontosa cichlids are easily recognized by their alternating black and blue stripes and prominent foreheads. They grow to about 8-10 inches.
- Lemon cichlid (Neolamprologus leleupi). These fish are bright yellow and grow to about 5 inches in length.
- Golden Julie cichlid (Julidochromis ornatus). The golden Julie stays between 3-4 inches at mature size and features a mottled black, yellow, and white pattern.
Other popular African cichlids include:
- Kribensis (Pelvicachromis pulcher)
- Jewel Cichlid (Hemichromis bimaculatus)
- African Butterfly Cichlid (Anomalochromis thomasi)
Central and South American Cichlids

Cichlids are found throughout Central and South America, with many species originating from the Amazon River. Central American species are considered to be more aggressive than their South American counterparts, but this will vary from species to species.

In comparison to African cichlids, these fish are much less aggressive. In fact, some can be kept in a community tank setup given the right environment.

Here are some of the most popular Central American cichlids:
- Red devil (Amphilophus labiatus). The red devil is named after its pale-red coloration and aggressive temperament. These fish reach a maximum size of about a foot.
- Convict cichlid (Amatitlania nigrofasciata). Growing to 3-5 inches, the convict cichlid is named after its alternating black and white stripes.
- Jack Dempsey (Rocio octofasciata). The Jack Dempsey reaches mature size at about 10 inches in length. These fish have bluish-green coloration with iridescent spots.
South American cichlids are some of the recognizable fish in the aquarium hobby, like the freshwater angelfish, though most keepers don’t even know that they’re cichlids! Here’s a list of a few you might recognize:
- Green terror (Andinoacara rivulatus). A beautiful fish, the green terror is a very aggressive cichlid. These fish are electric blue, yellow, and orange, and can grow up to a foot in length.
- Ram cichlid (Mikrogeophagus ramirezi). One of the most community-friendly cichlids, the ram cichlid can be easily bred in the home aquarium. These blue, yellow, and red fish stay relatively small, usually under 4 inches.
- Angelfish (Pterophyllum scalare). An odd-looking cichlid, the freshwater angelfish is a type of South American cichlid! Angels come in a variety of natural blacks, browns, and silvers, and can reach a height of 12 inches.
- Discus (Symphysodon spp.). Considered to be one of the most challenging cichlid tank setups to maintain, discus come in all colors. They grow to be about 6-10 inches and can be bred in the home aquarium.
- Severum (Heros severus/Heros efasciatus). Another relatively peaceful fish, the severum comes in a variety of colors, ranging from very bright to dull. They reach mature size between 6-8 inches.
Best Tank Mates

As you can see, there are many different species of cichlid! Even though they’re all related to the Cichlidae family, most of these fish cannot be kept with one another. Instead, cichlid tank mates are very limited. In most cases, species can only be kept with their own species. In some of the more niche African cichlid communities, fish can only be kept with other fish from their exact natural habitat.

When picking cichlid tank mates, aggression needs to be considered first, but tank size and setup need to be considered as well. For example, African cichlids originate from much more basic and harder water parameters than the low acidity and softness found throughout South America. While cichlids aren’t overly active fish, they need a lot of space to create territories.

This is the single most important rule for cichlid tank mates: don’t attempt it in a small tank. A 55-gallon is the minimum for most African cichlid setups, and even then stocking order is critical. The bigger the tank, the more territory gets distributed and the less any one fish dominates. Combinations that fall apart in a 55-gallon often work fine in a 75 or 90-gallon.

The biggest mistake I see is hobbyists ignoring water parameter differences. African cichlids need hard, alkaline water. South American community fish like tetras and corydoras prefer soft, acidic conditions. Mix those together and even if the aggression doesn’t kill anything, the wrong parameters will stress every fish in the tank. Know your cichlid’s water chemistry requirements before picking any tank mate.

With all this considered, here are some of the best tank mates for African, Central American, and South American cichlids.

African Cichlids

There are many species of cichlid across the continent of Africa. In most cases, fish that originate from the same region can be kept together. Even then, there is room for aggression.

Let’s first consider the best tank mates for Lake Malawi species.

Lake Malawi tank mates

Lake Malawi African cichlids are considered to be more aggressive than Lake Tanganyika species, so tank mate pairing and ordering are especially important.

Mbuna species. Members of the Labidochromis, Pseudotropheus, and Melanochromis genera do best when kept together. These are colorful fish that can be mixed and matched in a 55 gallon aquarium. It is recommended to keep about 10 individuals per 55 gallon, paying extra attention to the stocking order.

Mbuna cichlids need plenty of rock in their aquarium to set up territories. The most aggressive species should be added last to prevent competition.

From personal experience: tiger barbs, rainbow sharks, and pictus catfish can all hold their own in a well-set-up Mbuna tank. Tiger barbs are fast and assertive enough to avoid becoming targets. Rainbow sharks are naturally territorial. they stake out their own section and cichlids tend to respect it. Pictus catfish are quick, nocturnal, and generally left alone. None of these are guaranteed, but with a large tank and plenty of rockwork, these combinations can work.

Aulonocara species. Peacocks are considered to be less aggressive than Mbuna species, but they’re still aggressive cichlids. In most cases, they can’t withstand the aggression of Mbunas, making these two species incompatible tank mates. Instead, peacock cichlids can be kept with each other, and more docile haps (Haplochormis spp.).

These fish also depend on the rockwork to form territories, so it’s important to incorporate plenty of caves and hiding spots for the fish. Aulonocara and Haplochormis have comparable aggression levels, but this may vary between specific species. Fish may be added together if they’re the same size, or be added later on according to size.

Lake Tanganyika tank mates

While Lake Tanganyika African cichlids are generally less aggressive than those from Lake Malawi, special attention is still needed to create successful tank mate pairings.

Shell-dwellers. There are a few different species of shell-dweller, including those from the Neolamprologus and Lamprologus genera. These freshwater fish defend their shell territories at the bottom of the tank, so tank mates should stay in the upper portions of the tank. Aggression can vary from species to species, but some tank mate options include:
- Sardine cichlid (Cyprichromis leptosoma)
- Julidochromis spp.
- Neolamprologus brichardi
Frontosas. These are some of the more peaceful fish on this African cichlid list, but they’re still capable of harassing and eating other fish. Frontosas do well in a species-only aquarium but can be kept with a few other Lake Tanganyika species, like the lemon cichlid or Judiochromis transcriptus. Some cichlid enthusiasts have even had luck keeping frontosas with shell-dwellers if the tank is set up with both species in mind.

Julidochromis spp.. Species from this genera can be kept with a few different African cichlids. Along with shell-dwellers and frontosas, Julidochromis could potentially be paired with sardine cichlids and Neolamprologus species.

Other African cichlid tank mates

In general, African cichlids should only be kept with related species. These are some of the most aggressive fish available in the hobby, and any fish tank mate pairing can fail. Because of this, hobbyists usually only recommend Synodontis catfish for these aggressive cichlid species.

Synodontis catfish (Synodontis spp.).These are nocturnal fish, which can help decrease the possibility of aggression. Some species only grow to be 4 inches, so they should not be kept with larger cichlids. They originate from Lake Tanganyika and do best with other endemic species, like frontosas and members of both Neolamprologus and Julidochromis. Popular species include S. lucipinnis, S. angelicus, and S. eupterus.

Given a large tank with plenty of hiding spots, Syndontis have also been successfully kept with Mbunas and Aulonocara peacocks.

Synodontis and pictus catfish are two of my personal top picks for African cichlid tanks. Both are fast, tough, and occupy different parts of the water column than most cichlids. exactly what you want. They’re not pushovers, and that matters in an African cichlid setup.

Rainbowfish (Melanotaeniidae family). Some hobbyists add rainbowfish, like Boesemani (Melanotaenia boesemani), to their African cichlid tank setups. These smaller, fast-moving fish act as dither fish which can help diffuse overall aggression.

Central and South American Cichlids

If you want a little more wiggle room for cichlid tank mates, Central and South American species are generally much more peaceful than their African counterparts. For some of these cichlids, it’s still recommended to only keep other species from Central and South America.

Aggressive tank mates

Central and South American cichlids can greatly vary in size and aggression. Species like red devils and green terrors are large freshwater fish. Even if a given species is not aggressive, they will readily eat smaller fish.

Here are some of the best tank mates for large and/or aggressive Central and South American cichlids:

Giant gouramis (Osphronemus goramy). Giant gouramis need a giant tank. They reach impressive sizes and can become increasingly aggressive as they grow. While native to Southeast Asia, these fish can be kept in a cichlid tank with oscars, severums, and geophagus.

Catfish. Most species of catfish can be kept with both peaceful and aggressive cichlids. An aggressive Central and South American cichlid tank can house Synodontis catfish, Raphael catfish (Platydoras armatulus), Redtail catfish (Phractocephalus hemioliopterus), and Pictus catfish (Pimelodus pictus).

Keep in mind that some catfish, like the redtail catfish, can grow to extreme sizes.

Arowana (Osteoglossidae family). Arowanas are one of the largest fish available in the aquarium trade, but they’re relatively delicate. It is not unheard of for especially aggressive species to chase after and attack arowana. Unfortunately, arowanas can quickly succumb to injury. In return, large arowanas also have the potential to eat smaller, calmer cichlids. In some cases, this pairing can work.

Other cichlids. The best cichlid pairings are ones that stay true to what you would find in their natural environment. Pick species that naturally occur in the same regions as your desired cichlid. Set up the tank so that each fish has its niche within that space. While this still isn’t guaranteed to work, it’s one of the best ways to approach any cichlid aquarium setup.

Community tank mates

It’s always risky adding more peaceful fish to a cichlid tank, but some hobbyists have made it work. These pairings will largely depend on the temperament of your freshwater fish, but success can be increased by providing plenty of hiding spots and paying close attention to interactions. Luckily, these species are usually much more peaceful than African cichlids, so there are some choices!

Here are some common community tank species that might fit in a Central or South American cichlid setup. Note any cichlid larger than 8 inches may consume them:

Giant danios (Devario aequipinnatus). Giant danios are possible tank mates for cichlids: they’re big, fast, and stay at the top of the water, away from predators. This doesn’t make them an instant success, however. Many hobbyists have found that their giant danio numbers start to dwindle the longer they stay in the tank. Make sure to watch out for aggression and be ready to rehome fish if necessary.

Rainbowfish. Species like the Boesemani rainbowfish (Melanotaenia boesemani), millennium rainbowfish (Glossolepis pseudoincisus), and the turquoise rainbowfish (Melanotaenia lacustris) have been known to make good tank mates for certain cichlids. Rainbows need to be kept in groups of at least 6 or more but are generally capable of escaping an attacking cichlid.

Swordtails (Xiphophorus hellerii). If you have cichlids that mind their own business, then swordtails could help bring some color and movement to the top of the aquarium. These fish are colorful and busy, but most importantly, they’re prolific. This is especially helpful as even if a cichlid goes after adults or eats the majority of fry, chances are that a swordtail population will be able to sustain itself.

Congo tetras (Phenacogrammus interruptus). Another similar option is the Congo tetra. These are moderately-sized schooling fish, just big enough to hold their own against a more territorial cichlid. Congo tetras are one of the few species of tetra that can be housed with cichlids, as anything smaller could be bullied or eaten.

Peaceful Cichlid Tank Mates

Some cichlids simply get along with fish while others are actually peaceful species. So much so that some hobbyists don’t even realize they’re cichlids, like freshwater angelfish! While African cichlids are still too aggressive to make this list, there are plenty of other Central and South American species that can successfully be added to a community tank.

Rams

The ram cichlid is a small South American species that can be kept and bred within a community tank setup. These fish only grow to about 4 inches, which means that they can be kept with both bigger and smaller species.

Some compatible ram cichlid tank mates include:
- Livebearers
- Corydoras catfish
- Tetras
- Angelfish
- Discus
It’s important to note that ram cichlids prefer slightly higher water temperatures than normal, in the 78 to 85° F range. Tank mates should be able to adapt to these conditions without any ill effects.

Angelfish

Freshwater angelfish are arguably the most popular species of cichlid, though many hobbyists don’t even realize that they’re cichlids. These fish require some special care when choosing tank mates as they prefer slow-moving water conditions and cannot tolerate having their fins nipped.

These are some options to consider:
- Other angelfish
- Mollies
- Rainbowfish
- Corydoras catfish
- Molly Fish
- Certain tetras (Cardinal tetras, Rummynose tetras)
Discus

Discus are one of the more challenging species of aquarium fish to keep due to their need for near-pristine water parameters and higher water temperature ranges. Because of this, many hobbyists choose to keep discus in setups by themselves, but some have also had luck keeping them in community tanks.

Some suitable tank mates might be:
- Dwarf gouramis
- Corydoras catfish
- Ram cichlids
- Angelfish
- Certain tetras (Cardinal tetras, Rummynose tetras, Neon tetras)
Oscars

Oscars can be aggressive, but they don’t mean to be. Instead, these are gentle giants that need plenty of space for themselves and might mistake smaller fish for a meal. Given the right setup, they are very easy to care for and can be kept with a variety of species, including:
- Silver dollars
- Clown loaches
- Arowanas
- Other cichlids (Green terror, Jack Dempsey, Severums)
- Other oscars
Severums

Severums are another relatively peaceful species of cichlid. These are large fish, growing to nearly 10 inches at adult size, but they can bring a lot of color and interest to a semi-aggressive community tank. They need a large tank, but can be kept with an assortment of:
- Silver dollars
- Denison barbs
- Pearl gouramis
- Oscars
- Other severums
FAQS

What kind of fish can be put with cichlids?

African cichlids have limited tank mates while Central and South American species can be kept with a bigger assortment. In general, African cichlids should only be kept with species that originate from the same regions. Central and South American species have greater flexibility for being mixed with each other and with other aquarium species.

Can you put a cichlid in a community tank?

Yes! Some cichlids can be kept in a community aquarium setting, like rams, angelfish, and discus. This means that they can be kept with more familiar tetras, cory catfish, and livebearers. However, more aggressive types, like African cichlids, should only be kept with each other.

Do cichlids eat other fish?

Yes, cichlids, especially large ones, can eat other fish. This isn’t entirely on purpose for some species, like the oscar, where curiosity gets the best of them. It is always safe to assume that if a fish can fit in another fish’s mouth, they could potentially become lunch.

African cichlids and more aggressive South American cichlids are more likely to chase and attack fish than they are to mistakingly eat them.

Can cichlids live with goldfish?

No! Cichlids can never live with goldfish. Goldfish are coldwater fish while cichlids prefer tropical and above tropical water temperature conditions. Many African cichlid species also prefer harder and more basic water conditions, which is incompatible with goldfish. Lastly, goldfish are gentle and relaxed while cichlids are active and territorial!

Expert Take

‘Cichlid tank mates’ is too broad a question without knowing which cichlid. Convict cichlids and discus are both cichlids, but the compatibility requirements are completely different. The universal rule: find out your cichlid’s aggression tier and maximum adult size, then stock accordingly. Most cichlid tank mate failures come from people not understanding what their cichlid will eventually become. — Mark Valderrama, AquariumStoreDepot

Hard Rule: Never mix cichlids from different aggression tiers. Putting a firemouth cichlid with an oscar doesn’t moderate the oscar’s behavior — it just gives the firemouth somewhere to hide while it deteriorates.

Mark’s Pick: For most cichlids, the safest tank mates are large, fast, robust species that can escape aggression and don’t trigger territorial responses. Larger catfish — plecos, large cory groups — or similarly-sized cichlids of a different species and compatible aggression level often work best.

Who Is This Setup Right For?

Good Fit If:
- You’ve researched your specific cichlid species’ adult size and aggression tier before stocking
- You have a large enough tank — 55+ gallons minimum for most cichlid species — with hiding spots and territory breaks
- You’re adding the cichlids last after other fish are established
- You enjoy active, personality-driven fish and are comfortable managing occasional aggression
Avoid If:
- You don’t know your cichlid’s adult size or behavior — many cichlids double in size in the first year
- You’re mixing cichlids from different lakes or aggression tiers without research
- You want a fully peaceful community — even the most peaceful cichlids have territorial phases
- You have delicate or slow-moving fish that can’t handle occasional aggression or are too small to survive it
Conclusion

When setting up a cichlid tank, you need a plan. These are aggressive fish that have special considerations regarding water parameters, tank setup, and aggression. Tank mates will largely revolve around the type of cichlid you choose to keep. An African cichlid tank might only leave room for related species but an angelfish aquarium might allow space for a variety of community species.

Keep in mind that while one pairing works for another hobbyist it might not always work for you. Always be ready to rehome fish if necessary.

📘 Want to learn more? This article is part of our complete Freshwater Fish Guide. your ultimate resource for freshwater species, care tips, tank setup, and more.
April 8, 2024
Why Angelfish and Guppies Are a Deadly Combo: What I’ve Seen After 25 Years
Angelfish and guppies look like an easy pairing on paper. both are tropical, both are popular, and their water parameters overlap enough that it seems to make sense. But I’ve seen this combination go wrong many times. Once angelfish start breeding, they become a completely different fish. The guppies that were swimming around unbothered suddenly become targets. and often end up as a meal. In this article I explain exactly why these two species don’t mix, and what to keep with your angels instead.
Key Takeaways
- Angelfish and guppies are two beginner species that are incompatible with each other.
- Guppies like active, neutral conditions while angelfish thrive in stagnant, acidic environments.
- Angelfish can grow to moderate sizes and will eat smaller fish and fry.
- Some of the best tank mates for angelfish are tetras, rainbowfish, and other cichlids.
Intro To Angelfish

Before we can understand why guppies are incompatible with angelfish, we need to understand angel requirements on their own. These fish have been in the aquarium hobby for a long time, and the understanding of their care has changed throughout the decades.

Angelfish are a type of tropical cichlid. The most common species to find in the aquarium hobby is Pterophyllum scalare, but you may find others available in more specialized fish stores. These fish originate from the Amazon River system throughout South America, specifically from parts of Brazil, Colombia, and Peru. They are found in slow-moving waters, dense with vegetation. They prefer more acidic conditions, closer to blackwater environments.

Luckily, most angelfish available for sale have been commercially bred, which led to more ethical sourcing and better-controlled health. There are also many varieties of angelfish available, but most display plain colors of browns, blacks, and silvers. At adult size, they can grow to be 6 inches long and 8 inches tall. Some individuals even grow to an impressive 1 foot in height!

Tank Setup

There has always been a lot of discussion surrounding angelfish tank size. They aren’t overly active fish, but they can grow to considerable sizes and exhibit some aggressive behavior. Because of this, the current recommendation is a 40 gallon for keeping them with multiple angels or other fish species, and a 20 gallon for a pair. Because of their height, they are one of the few fish that do better in a tall aquarium than a long one.

This aquarium should have minimal water flow with plenty of plants and organics that lower the water pH.

Behavior

As a cichlid, these fish are mildly aggressive. They are not fast swimmers and will stick to the middle and upper portions of the water column. Male angels are likely to establish territories throughout the tank, especially during breeding periods. Females can be just as aggressive as males in some cases.

This is the part most people don’t anticipate. An angelfish that ignored guppies for months can turn predatory the moment it starts breeding. I’ve seen it happen. guppies that coexisted fine suddenly start disappearing once the angels pair off and claim territory. Breeding flips a switch in them, and small, fast-moving fish like guppies become threats to be chased or food to be eaten.

As slow swimmers, they are also slow eaters. This behavior is especially important to keep in mind when picking other tank mates as a shy angel could be outcompeted.

One last thing to consider is that, while semi-aggressive fish, angelfish can be skittish. Because of this, many hobbyists keep their angelfish aquariums dimly lit and stained with tannins.

Intro to Guppies

A guppy fish is likely to be one of the first tropical fish you ever get. These are small, hardy fish that bring a ton of color and excitement to the aquarium. They’re very forgiving of incorrect water parameters and will continue to breed regardless. All this, in addition to their wide availability and affordable price, make them a perfect beginner fish¹.

That’s the problem, though: guppy fish are perfect beginner fish. What happens when you want to move on to more advanced species, like the angelfish? Can you keep guppies and angels in the same tank?

In most cases, guppy fish cannot be safely kept with angelfish. It might be hard to understand why, as these fish have many overlapping requirements, but we’ll see what makes these two fish species incompatible in the long run.

Mature Size

Guppy fish are small fish with males staying under 1.5 inches and females maxing out at around 2.5 inches. While this makes it so that a lot can be kept in a little, these tiny fish also make an enticing snack for larger angelfish.

Though unlikely, any fish is capable of eating something that can fit in their mouths. Small guppies, as well as guppy fry, are a quick and easy snack for a mature angelfish.

Tank Setup

Guppies can pretty much be kept in any aquarium setup imaginable, but the same cannot be said for angels. As mentioned before, angelfish prefer near-blackwater conditions in dim lighting conditions. While the two species enjoy an abundance of live plants, their compatibility in terms of tank setup ends there.

Guppy fish are often kept in neutral water parameters, with a pH near 7.0. While they can be acclimated to more acidic conditions, it’s best to keep fish close to their original environments. This is also true for the amount of water flow present in the fish tank. Guppies enjoy swimming against a current, whereas angels will be pushed into the corner by nearly any trace of water movement.

Another important aspect to keep in mind is that guppies are prolific breeders. The more space and resources they have, the more they will reproduce. In general, guppy fish can comfortably live in a 10 gallon aquarium. At one point or another, adult and/or baby guppies will need to be removed to maintain a healthy balance in the aquarium.

Aqueon 10 Gallon Tank

Your standard 10 gallon tank. Goes on sale at local Petcos for cheap

Buy On Petco Buy On Amazon

If placed in a very large tank, removing excess guppy fry can be difficult, even though your angelfish will likely help maintain populations. As we’ll see, an increase in guppies can lead to numerous problems for the angels in regard to opposing behaviors.

Behavior

On paper, it would seem that you could keep guppies and angelfish together. But when kept together in the same aquarium, these fish couldn’t be any more different.

Angelfish might as well have the exact opposite behavior as guppies. Angels are slow-moving and relatively reserved. Guppies are front-and-center and constantly moving! While this pairing of behaviors might work for other fish species, it does not work for these.

Guppies are simply too overbearing for angels. They stay in the same portions of the aquarium as angels and can stress angelfish out. Keep in mind that just because your angelfish is supposed to be semi-aggressive does not mean that you can’t get a shy one. This is especially true during feeding times when angelfish like to take their time and eat while guppies go into a frenzy. This incompatibility can lead to overly aggressive or starved angels.

Angelfish are a much more reserved, observational fish. I’ve watched angels in high-activity tanks stop coming to the surface to eat and start retreating into corners. An angelfish that stops eating is already in trouble. The constant movement and surface activity of guppies is genuinely stressful for a fish that prefers slow, dimly lit, plant-heavy conditions.

While guppies aren’t aggressive fish, they have been known to be fin nippers. If an angelfish spends a significant amount of time in the upper water column, they may start to get bullied by the other guppies. This can be damaging as angelfish are already prone to snagging their extended finnage and developing fin rot. Similarly, an aggressive angel might chase and nip at pesky guppies that invade their territory.

While it might seem like guppies and angelfish can go in the same tank, the differences in their behaviors ultimately make them incompatible.

Why Angelfish and Guppies Don’t Work

Can you put guppies and angelfish together? No.

While these fish are two of the most popular fish species available, they cannot be kept in the same aquarium. This is because:
1. Guppies are small, peaceful fish that can quickly become food for a larger angel. Guppy fry will also be regularly consumed by hungry angelfish.
2. Angelfish prefer water parameters that resemble their natural habitat. This is slow-moving water with low pH. Guppy fish can be acclimated to a lower pH, but prefer a moving water current with near-neutral water quality. Angelfish also prefer dim settings while guppies shine under bright lights.
3. Guppies can quickly overrun a larger fish tank as they are prolific breeders. A healthy balance between guppies and angels may be difficult to maintain while keeping parameters in check.
4. Guppy fish and angelfish have opposite behaviors. Angels are large semi-aggressive fish that can bully smaller fish, or be bullied if the individual is shy. This is especially true during feeding times when guppies are quick to eat.
Better Alternatives

Though guppies and angelfish might not work together, there are plenty of ways to still use both of these species in their own respective community tank setup.

Some of the best guppy fish tank mates include:
- Other livebearers
- Tetras
- Rasboras
- Corydoras catfish
Depending on the individual personality of your angel, you may be able to set up a community aquarium. If you have an angelfish that shows territorial behavior, then you may need to include some of the more aggressive species. Unfortunately, there is no way to tell how angelfish will react to new fish, so you might need to rehome tank mates if things don’t work out. To help avoid this, it’s recommended to add other fish to the tank before adding the angels.

From my experience, rainbowfish and Congo tetras are two of the best alternatives. both are large enough that angels won’t see them as prey, and both are active without being overbearing. For more advanced aquarists, discus are an excellent pairing with angelfish; they share the same slow-water, warm, slightly acidic preferences and have a similar calm temperament. Just be prepared for the water quality demands discus require.

Some community tank mate options for angelfish include:
- Corydoras catfish
- Gouramis
- Rainbowfish
If you have angels that display territorial behavior, then you might consider these tank mates instead:
- Severum
- Electric blue acara
- Kribensis
- Other angelfish
In order to keep a group of angelfish together indefinitely, fish should be added to the aquarium at the same time. At least 5 or more can comfortably be kept in a mid-size tank as long as there is a balance of males and females.

Can different species of angelfish be kept together in the same tank?

As mentioned before, there are a couple of different species of angelfish available in the aquarium hobby. One of these includes the relatively rare–and expensive–altum angelfish (Pterophyllum altum).

For the most part, hobbyists agree that these two species can be tank mates as long as a large tank is allowed. It is also recommended to add the two species together to help diffuse any possible aggression. A rehoming plan should be used in case the pairing doesn’t work out.

Which fish can be kept with angelfish?

Angelfish can be kept with certain tetras, gouramis, severums, or acaras. They cannot be kept with guppies and generally don’t do well with any species of livebearer.

What fish are compatible with guppies?

Angelfish can be kept in pairs with each other, in a community tank setup, or in a semi-aggressive setup. Depending on the plan you have for your tank, you may want to try breeding angels. Otherwise, your angel’s personality will decide whether you keep a community aquarium or a more predatory fish setup.

How many angel fish should be kept together?

Angelfish can be kept in pairs of two or in small groups of 5 or more. This will be determined by the size of your aquarium and the temperament of your fish.

Do angelfish eat other fish?

Angelfish have small mouths, but they will likely try to eat smaller tank mates. They will especially love trying to catch baby guppies!

Can you put angelfish with mollies?

While you can’t really keep guppies and angelfish together, do mollies work?

Many of the same concerns arise with mollies as when keeping angelfish with guppies: natural habitat differences, and opposing behaviors. However, mollies are considerably bigger than guppies and slightly less active. Full-grown angelfish will still see smaller mollies as snacks, but the two species are slightly more likely to be compatible tank mates in the long run.

Conclusion

Guppies and angelfish are two of the most popular beginner fish species available, but unfortunately, they do not make good tank mates. There are simply too many differences between preferred water conditions and behaviors that make it likely for either your angels or guppies to get hurt in the process. Depending on the personality of your angelfish, other suitable tank mates might be tetras, gouramis, corydoras, or other cichlids.

📘 Want to learn more? This article is part of our complete Freshwater Fish Guide. your ultimate resource for freshwater species, care tips, tank setup, and more.
April 7, 2024
7 Best Turtles for Aquariums: My Picks After Keeping Sliders
I’ve kept red-eared sliders, and I’ll tell you upfront: aquarium turtles are a bigger commitment than most people expect. They live for decades, grow surprisingly large, and produce more waste than their size suggests. But they’re also some of the most interactive and personable animals you can keep. rewarding in a way that fish simply can’t replicate. In this guide I cover 7 of the best aquarium turtle species and give you the honest care information you need before bringing one home.
Key Takeaways
- There are many different types of freshwater turtles in the aquarium trade, and each has its own unique needs and preferences
- Captive-bred turtles can make fascinating pets, although they do not like to be touched or handled
- Aquariums can make excellent turtle habitats, although these amphibious reptiles require some dry land in their tank where they can bask
- Your turtle’s tank must include a basking platform or secure floating log where your pet can crawl out to warm up
- Turtles also need a special UV bulb if kept indoors. This essential requirement helps turtles make vitamin D and absorb calcium.
7 Best Turtles For Aquariums

1. Red Ear Slider
- Scientific name: Trachemys scripta elegans
- Care level: Intermediate (Suitable for beginners)
- Temperament: Calm and friendly but does not enjoy being handled
- Minimum tank size: 50 gallons
- Potential lifespan: Up to 40 years in captivity
- Recommended temperatures: 70-85°F ambient, 85-90°F basking spot, 75-85°F water
The red-ear slider is the first species on my list because these colorful reptiles are one of the most popular and attractive pet turtle species in the world! These turtles are suitable for beginners, although they need regular care and water quality maintenance to stay healthy.

This species is easily available from pet stores, but you can often find mature specimens up for adoption too. These large and colorful reptiles are naturally beautiful, although albinos and various other awesome morphs are available from breeders.

Keeping these wonderful animals is a long-term commitment since they can live for over 30 years. Red-eared sliders can reach 12 inches when full-grown, so they need an enclosure of at least 50 gallons for long-term care.

The red-eared slider is my personal top pick, but I want to be upfront: they require significant planning. A juvenile slider looks manageable in a small tank, but within a few years you’re looking at a 12-inch reptile needing 75. 100 gallons of clean water, a powerful canister filter, and a proper basking setup. Sliders that are improperly housed are among the most frequently rehomed turtles in the hobby. Have a realistic plan for the adult setup before you buy the juvenile.

2. Striped Mud
- Scientific name: Kinosternon baurii
- Care level: Intermediate
- Temperament: May scratch and bite, should not be handled
- Minimum tank size: 30 gallons
- Potential lifespan: Up to 50 years
- Recommended temperatures: 80-85°F ambient, 87-92°F basking spot, 75-80°F water
The striped mud turtle is a small species that grows a shell length of just 3.5-4.5 inches. Despite their size, these miniature creatures can live for half a century with good care!

These turtles are characterized by three pale stripes on their oval shell, although these markings may fade as the animal matures. They are omnivorous turtles that feed on invertebrates and plant material in the wild.

Striped mud turtles can be kept in a smaller tank than the red-eared slider, although they require good water quality, UVB bulbs, and a suitable basking area just like other species.

3. Spotted
- Scientific name: Clemmys guttata
- Care level: Intermediate
- Temperament: Alert and active but does not enjoy handling
- Minimum tank size: 30 gallons
- Potential lifespan: Up to 50 years
- Recommended temperatures: 80-85°F ambient, 95°F basking spot, 70-75°F water
The spotted turtle is an attractive North American species that grows to about 5 inches or so. These turtles are identified by their dark overall coloration and yellow spots on the head and upper shell.

Spotted turtles will eat some plant matter, although they are mostly carnivorous. Captive specimens will thrive on quality commercial pellets supplemented with meaty foods like worms and crickets.

These turtles are not the best swimmers, so keep their water shallow enough for them to breathe at the surface while standing and provide plenty of dry land where they can hang out and bask.

4. Maps
- Scientific name: Graptemys spp.
- Care level: Intermediate-advanced
- Temperament: Naturally active but shy around people
- Minimum tank size: Species dependent. Large species may require over 100 gallons
- Potential lifespan: Can live for over 30 years
- Recommended temperatures: 75-85°F ambient, 90-95°F basking spot, 70-80°F water
Map turtles are some of the most beautiful semi-aquatic turtles available in their pet trade. There are many species, and some have interesting patterns on their skin and shells and textured scales on their upper shells (carapaces) that make them excellent display animals.

However, map turtles require very clean living conditions and a varied diet. They are not recommended for beginners, although dedicated turtle keepers with moderate experience should have no problems.

5. Musk
- Scientific name: Sternotherus odoratus
- Care level: Intermediate
- Temperament: May scratch and bite. These turtles should not be handled
- Minimum tank size: 30 gallons
- Potential lifespan: May live for over 60 years
- Recommended temperatures: 83-86°F ambient, about 90°F basking spot, 72-78°F water
Common musk turtles (also known as stinkpots) get their name from the smelly odor they produce when frightened, although captive-bred pets are less likely to react this way once they get used to you.

These small aquatic turtles grow to about 4 inches and spend most of their time in the water. However, they require a dry basking spot just like the other species in this list.

Musk turtles are suitable for beginners and their small enclosure requirements make them a popular choice for people with limited space.

6. Diamondback Terrapins

View this post on Instagram

A post shared by Diamondback Terrapin (@diamondbackterrapin)
- Scientific name: Malaclemys terrapin
- Care level: Intermediate
- Temperament: Generally peaceful but may bite if handled
- Minimum tank size: 55-75 gallons
- Potential lifespan: Up to 40 years
- Recommended temperatures: 80-85°F ambient, about 90°F basking spot, 75-78°F water
Diamondback terrapins are the only species on this list that aren’t naturally found in freshwater habitats. These colorful reptiles are at home in brackish water systems along the East and Gulf coasts of North America. While captive-bred specimens are often kept in freshwater, you will need to increase the salinity to create conditions that match their natural habitat.

This is a medium-sized species and females can reach a shell length of about 9 inches. In common with many other turtle species, the males are much smaller, maxing out at a shell length of about 5 inches.

Diamondback terrapins are carnivorous reptiles that feed on small animals like snails. However, captive specimens do well on commercially sold turtle foods like floating sticks.

7. Eastern Box Turtle

View this post on Instagram

A post shared by Eastern Box Turtle (@eastern.box.turtle)
- Scientific name: Terrapene carolina carolina
- Care level: Advanced
- Temperament: Generally docile but males can be aggressive toward each other
- Minimum enclosure size: Approximately 15 square feet
- Potential lifespan: May live for over 50 years
- Temperature requirements: 65-75°F ambient, 80-90°F basking spot
Box turtles are unique land-dwelling reptiles with a high, dome-shaped shell that can be closed off with a special hinge on the lower shell (plastron). There are several species of box turtles in North America, although the Eastern box turtle is one of the more commonly available captive-bred pet species.

These colorful reptiles are not suitable for aquariums due to their mostly terrestrial nature, although they love soaking in water and they can swim and even submerge themselves. They should be kept in large outdoor enclosures, preferably planted with vegetation that will provide shade and shelter. However, they can also be kept in large indoor terrariums if you manage the temperature and provide UV lighting.

Before You Pick One

There are many different turtle species available in the hobby, so choosing the perfect species can be tough if you’re just getting started. Here are four quick tips for choosing your first turtle.
- A Long-term Commitment
Some turtles can live for over 50 years, and many of them outlive their owners. Many turtles that are bought as juveniles will outlive their first owners, so consider buying an adult or adopting a pet from someone who can no longer care for it.
- Insist on Captive-bred
Your turtle’s health should be your first priority, so choose healthy, captive-bred animals and never buy animals that were taken from the wild. I recommend choosing a species that is easily available and easy to care for.
- Turtle Tank Size
You’ll notice that each species has a different minimum tank size, although your turtle will definitely appreciate a larger habitat. Some turtles need very large enclosures when they reach adult size, so factor this in when choosing your pet.
- Plan Ahead
It’s important to consider your new turtle’s care requirements and create a suitable habitat before you bring it home – it will be a whole lot less stressful for you and your pet!

Care – The Basics

Enclosure size

Freshwater turtles can be kept in aquariums, large plastic containers, or even indoor ponds. The size of their habitat will depend on the size of the species, although your pet will appreciate plenty of room to explore. Small species like mud and musk turtles can be kept in enclosures as small as 30 gallons, while larger types may need enclosures of at least 5 feet long and wide. A 55 gallon tank is usually a good start for many of the turtles on this list.

55 Gallon Aquarium

The 55-gallon aquarium is a great budget-friendly larger tank. It often goes on sale at chain pet stores.

Buy On Petco Buy On Amazon

Basking Spot

Most freshwater turtles leave the water regularly to bask in the sun. They do this to warm their bodies and absorb Ultraviolet rays. A turtle tank must include a dry area where your pet can hang out above the water line.

A floating shelf above the water is a great option as it does not take up any swimming space. However, the shelf must be secured below your tank lighting and be sturdy enough for your pet to climb on and off. You can see that egg crate plastic and acrylic can work for a turtle ramp.

View this post on Instagram

A post shared by Joanne Peter (@littlewingedwolf)

You can also use a large piece of driftwood or rocks to create a more natural look, although this can take up a lot of space in your turtle’s tank.

Layout

Fishkeepers enjoy creating beautiful underwater scenes in their aquariums, but experienced turtle keepers know to keep things simple. A tank without substrate, decorations, and plants is much easier to clean and maintain.

Care and Maintenance

Maintaining Water Quality

Turtles are surprisingly messy eaters and they produce plenty of waste. You will need good filtration to keep their habitat clean and maintain healthy water quality. Internal power filters and canister filters work well for turtles. Canister filters are usually preferred given the amount of waste a turtle can produce.

This is where most beginners go wrong. Turtles are significantly messier than fish. they eat messily, defecate in the water, and can overwhelm a standard aquarium filter rated for fish their tank size. I recommend running a canister filter rated for at least double your actual tank volume. And don’t underestimate tank size: a slider in a 40-gallon seems fine for a year, but you’re building a problem that costs more to fix later. Bigger tank and oversized filtration from the start will save you money and stress.

Great For Large Tanks

Fluval FX Series

High flow, large filtration capacity, and quality plumbing – The FX series is designed for monster fish keepers

Buy On Amazon Click For Best Price

Neglected turtles in dirty water are prone to health problems, so regular maintenance is really important. Perform regular water changes in your turtle tank and give it a thorough cleaning from time to time to maintain hygienic conditions.

Lighting

Turtles kept indoors need access to ultraviolet light to grow healthy bones and shells and to prevent a serious health condition called metabolic bone disease. Without a special UVB light, turtles cannot produce vitamin D and absorb the calcium they need to stay healthy.

While natural sunlight provides UVA and UVB light, most artificial light sources do not. Purchase a special UV bulb designed specifically for turtles and other reptiles. The light source should be positioned above the basking spot and be run on a timer for ten or more hours each day.

Zoo Med UVB Light

This UVB kit from Zoo Med offers a good value and is perfect for new turtle keepers

Buy On Petco Buy On Amazon

Heating

Turtles are cold-blooded animals that require external heat sources to warm their bodies. Your UVB bulb may double as a heat lamp or you may need to install a separate basking lamp to create the perfect temperature.

The water in your turtle’s tank may need to be heated with a fish tank heater to maintain a comfortable temperature. Use a thermometer to monitor the temperature and create a safe and comfortable environment for your pet.

Diet

Turtles are easy to feed, although a varied diet is recommended to keep them happy and healthy. Provide a pellet/stick food made for turtles and supplement it with some fresh foods like romaine lettuce, crickets, and mealworms.

Most species are omnivores that feed on insects and soft plant material, although different species have different diets. Be sure to research the needs of your pet to create a healthy meal plan.

Feeding

Overfeeding can cause health problems so fight the temptation to provide too many snacks! Young turtles can be fed every day while adult specimens should do well with a meal every other day.

Some turtle keepers move their pets to a separate container at feeding time so they can simply discard the dirty water and uneaten food to keep their main enclosure cleaner for longer. However, this is not recommended for new pets that are still adapting to their new home as unnecessary handling can be stressful.

Veterinary Care

Turtles are exotic pets that may need the care of specialist veterinarians. It’s a good idea to contact an exotic pet veterinarian in your area if your pet requires medical care.

What kind of turtle can live in a fish tank?

Some aquatic turtles can live with fish, although it is risky to keep them together because turtles will snack on fish and other small animals. Turtles also have different habitat requirements to fish, so it’s better to keep these reptiles in an enclosure designed specifically for their needs.

Is it OK to put a turtle in an aquarium?

Many aquatic turtles can be kept in glass aquariums, although they have some special requirements. Their aquarium must include a basking platform where they can crawl out of the water and a special UV light bulb to keep them healthy.

You should never take a turtle from the wild and keep it as a pet. Many species are now endangered in the wild, and captive-bred specimens tend to be much healthier and easier to care for anyway.

Can turtles live in a tank full of water?

Some aquatic turtles can be kept in a tank full of water, although some semi-aquatic turtles need shallow water so that they can keep their head above the surface. Almost all species will require a dry basking spot where they can climb out of the water and heat up.

Terrestrial turtles and tortoises should not be kept in water!

What is the easiest turtle to care for?

Musk and mud turtles are relatively easy to care for because they stay small and do not require a very large habitat. However, the larger red-eared slider is hardy and easy to care for if you have the space.

How big of a tank do I need for 2 turtles?

The minimum tank size for two turtles will depend on their age and species. You can keep a pair of small turtles in a tank of about 50 gallons, although larger animals will require more space.

Final Thoughts

Keeping turtles is great for people of all ages and each of the aquatic turtles in this guide make great pets if given a good home and properly cared for. I hope the information in this article has helped you choose your new friend for life and given you some insight into the basics of aquatic turtle care and husbandry.

My final advice for new turtle owners is to factor in their impressive lifespan, especially when buying a juvenile specimen. It’s also important to research the specific needs of the species you choose so that you can provide a happy home for your new companion!

Do you have an aquatic turtle tank? Tell us about your favorite species in the comments below!
March 29, 2024
Aquarium Water for Plants: What I’ve Learned After 25 Years of Freshwater Fishkeeping
I’ve been doing water changes on my freshwater tanks for over 25 years, and for most of that time I’ve been routing that water straight to my garden instead of down the drain. As long as your tank is freshwater and hasn’t been medicated, that nutrient-rich water is liquid gold for plants. I’ve seen the difference firsthand. Here’s everything you need to know about using aquarium water on your plants and why it works so well.
Key Takeaways
- Aquarium water is rich in macro and micronutrients, like nitrogen and phosphorus, that are commonly found in popular fertilizer options.
- The parameters of your tank water may be influenced by tap water, food ingredients, and fish output.
- Chemically treated water should not be used on edible plants.
- Aquaponics is a large field in agriculture and encourages growing plants in a fish-based system.
Why It Works

Before we can see how fish tank water can be used to feed terrestrial plants, we need to understand what makes this water special. Like anything in the aquarium hobby, it all ties back to the nitrogen cycle.

I’ve always thought of my water change water as free fertilizer. Instead of dumping it, I walk it straight to my garden beds. my freshwater community tanks produce some of the richest free plant food you can find.

When you cycled your tank, you needed to introduce a source of ammonia into your aquarium. This could have been done organically or chemically. After a while, beneficial bacteria started to reproduce and process the ammonia into other compounds, like nitrite and nitrate. Once enough bacteria had populated the aquarium, ammonia and nitrite could be maintained at 0 ppm while nitrate was controlled through water changes.

Just because ammonia and nitrite aren’t readable in your current tank through test kits doesn’t mean that they’re not present though. In fact, fish are constantly creating ammonia through respiration and waste. Most test kits don’t read to this precision.

Plants and Nutrients

If you have a freshwater aquarium, you may have been recommended to add live plants to help cycle the aquarium and to keep an overall healthy system. There is a good reason for this! As we’ll see, aquatic plants are very similar to terrestrial plants in how they rely on nutrients; aquarium plants get most of their nutrients through the water column, though sometimes through the substrate, and most terrestrial plants rely on the soil to receive nutrients.

Plants can absorb all of these nitrogen compounds: ammonium, ammonia, nitrite, and nitrate. Most species uptake nitrate the most, but live plants can help maintain the other levels. This is why adding live plants to an aquarium can decrease the toxicity of the water and maintain levels in the future.

It’s important to note that freshwater aquariums also contain other important compounds, like magnesium and phosphate, that aren’t regularly tested for. Just because hobbyists don’t monitor these parameters doesn’t mean they’re not present in the aquarium. As we’ll see, they’re some of the most important compounds for growing terrestrial plants!

How can our fish tanks help our indoor plants and possibly even help grow the food that we eat?

Plant Fertilizer

The next time you go into an outdoor store or gardening center, take a look at the available fertilizers. You may see a variety of powder and liquid options, each of which will provide a percent breakdown of the nutrients offered.

You will likely see a ratio of three values on the front, which read N-P-K¹, or nitrogen-phosphorus-potassium. These are some of the most important nutrients for plant growth, and the ratio needed will depend on the species of plant being grown.

While you likely won’t get this precise ratio with fish tank water, nitrogen, phosphorus, and potassium are present in your aquarium. While nitrogen is predictable, phosphorus, potassium, and micronutrient levels will vary as they are influenced by tap water, food ingredients, and other inputs.

Now that we know how aquarium water acts as a fertilizer, how can we use what we have?

Watering and Water Changes

The best way to use your aquarium water as a plant fertilizer is by not wasting what you already have! More than likely, you perform water changes on your aquarium anywhere from once a week to several times a month. Chances are that you’ve been throwing that old water down the drain.

Before you get rid of that water, get a watering can! Use an aquarium siphon or cup to remove the water from the tank and into your container. As long as there isn’t a ton of fish waste or other organic debris, this water can be directly used to water plants. It really is as easy as that!

Python Cleaner

The Python is a mainstay in the fish hobby. Easily clean your aquarium by connecting this to your sink!

Buy On Amazon

If you’re siphoning your substrate during your water change, then you may want to take some time to let that gunk settle at the bottom of your container. While it is unlikely to hurt your plants, fish waste left sitting on top of the soil can attract other garden pests and lead to a nasty smell.

But wait! Don’t throw that fish poop out either. In fact, this organic matter can be directly added to a compost pile along with any excess water.

Storing Water

Unless you have a ton of plants, you’ll probably end up with leftover water from your fish tank. This water can be discarded as usual, or you may consider setting up a reserve for later use.

This reserve is like setting up another fish tank but in a closed tub or bucket. Here is one way of setting up an aquarium water reserve:

Use a bucket, tub, or other large container. This container should not let light in as this will facilitate algae growth that will end up stealing nutrients. In the worst-case scenario, this nutrient-packed algae can be used for composting!

This container should also be closed so that no contaminants, like aerosols, insects, or a thirsty pet, can make their way in. If you use a trash cute, the Brute brand is a great mainstay in the hobby. Make sure it is labeled as food grade.

Use filter media. Contrary to popular belief, beneficial bacteria do not live in the water column. Instead, they live on the surfaces in our fish tanks, mainly in porous filter media. While new amounts of ammonia or nitrite are unlikely to enter your container, beneficial bacteria will continue to make your used fish tank water a healthy environment. You can also squeeze out your sponges during water changes to release some of the bacteria and the nutrients.

Install a pump. Even though this water will be processed by beneficial bacteria, stagnant water will still invite unhealthy microbes. Stagnant water will likely grow algae and other slime while also depleting the water of oxygen. This could create anaerobic conditions, which would not be healthy for ornamental plants.

Check your water regularly. Fish tank water won’t store indefinitely, and we don’t recommend hanging onto it for more than a week, especially if there is sediment or other organics present. If you notice a funky smell or any other signs of contamination, dispose of the water.

Indoor Plants In Your Aquarium

Aquarium water can be used to water plants with a watering can, but it can also be used straight from the source. Many hobbyists have begun growing indoor plants, and even some fruits and vegetables, straight out of their aquariums. This removes the need to store water and gives plants direct access to some of the best plant fertilizers available. In return, the plant helps remove excess nutrients from the water column.

In order to grow terrestrial plants out of your aquarium, you will need an additional grow light. Also, some plants cannot have constantly submerged roots, so some special selection is needed.

Considerations When Using Aquarium Water For Plants

Aquariums make some of the best plant fertilizers available, but you might have a few questions about keeping healthy fish and healthy plants.

Should you add more nutrients directly into your aquarium?

It would make sense that adding more nitrogen compounds and other nutrients to your aquarium would make your fertilizer even better, but aquariums have a delicate balance of parameters. Too much ammonia or nitrite can lead to poisoning your fish; even high levels of nitrates can eventually impact your aquarium.

However, many hobbyists add nitrogen additives to their aquariums to help their aquatic plants grow. In moderation, this is a great way to facilitate growth and even get more desirable colors out of your live plants. In terms of dosing other macro and micronutrients, like magnesium and phosphate, it’s generally not necessary unless you are certain your aquarium is lacking in them.

Editor’s Choice!

APT Complete

Editor’s Choice
Made by an aquascaper for aquascapers. This is the best all around aquarium plant fertilizer on the market. Marco and micronutrients in one bottle!
Use Coupon Code ASDComplete for 10% off your order!

Click For Best Price Buy On Amazon

Being able to water plants with fish tank water is an added benefit of your aquarium, not its main purpose (though we’ll discuss more in the aquaponics section later).

Should you be worried about aquarium chemicals?

Yes, there are some potential hazards associated with using fish tank water that has been treated with chemical products. This is especially a concern if using the water on edible plants.

Most hobbyists dose their fish tanks with at least one chemical. Most often, this is a dechlorinator that removes chlorine and chloramine to make water safe for fish, but can also include medications. However, most of these chemicals are not food-grade and cannot be ingested safely for certain. Some fish keepers use alternatives, like ascorbic acid, as a dechlorinator, but this takes some special measuring.

One product you might not consider a threat to plants is aquarium salt. Most plants cannot physiologically process salt and may start to die as a result. You should never use saltwater for a garden if you keep a marine tank.

⚠️ From my experience: The two setups I always warn people about are saltwater/reef tanks and African cichlid tanks. Reef tanks have obvious salt issues, but cichlid tanks also tend to run high pH and sometimes have added salt. both can damage or kill garden plants. Stick with a standard freshwater community tank and you’ll be fine.

If the tank has been medicated in the past or is currently being medicated, you should also not use the water on your garden.

In general, you should avoid using chemically treated fish tank water on plants you intend to eat.

Does pH matter?

So far, we have not discussed pH. Freshwater aquariums typically have a neutral pH of around 7.0, but some blackwater or cichlid tanks might have well above or below that. Most plants thrive in the neutral zone, though some species prefer acidic or basic conditions respectively.

Another important parameter to consider is alkalinity, or the ability of water to buffer changes in pH. This parameter is rarely discussed in freshwater aquariums, with general hardness being a bigger concern. However, a high alkalinity can also impede plant growth and start to affect the effectiveness of pesticides and other enhancers.

Aquaponics

If you’re serious about using your fish tank’s water to facilitate your plant growth, you might be interested in the greater field of aquaponics.

View this post on Instagram

A post shared by College of Agriculture & Natural Resources (@umd_agnr)

This takes growing plants with fish tank water to a whole other level. Simply put, aquaponics is sustainable farming using a closed-loop system that is dependent on the nitrogen cycle: fish create waste and the plants uptake the nutrients. Plants are grown directly in the water for easy nutrient uptake without the need for soil.

Some plants that can be grown in these systems include lettuce, tomatoes, peppers, and herbs.

Can I use fish tank water to water my plants?

Yes! Freshwater fish tank water is a great source of nutrients required for healthy plant growth, like nitrates. However, too much watering with aquarium water can overload your plants with nutrients, which can also be detrimental.

Is aquarium water conditioner good for plants?

If you’re planning on eating the foods you’re growing, you should not use chemically treated fish tank water. This is because these chemicals have not been evaluated for consumption. Instead, alternatives, like ascorbic acid, could be used to neutralize chlorine for fish.

Is fish tank water good for gardens?

Yes, you can use fish tank water on indoor and outdoor plants. Make sure to avoid plants that you will eat as aquarium water is often treated with various chemicals, like dechlorinator.

Conclusion

If you love aquariums and gardening, then there are many reasons to start using your tank water to feed your plants! Aquarium water is packed with important nutrients, like nitrate, that can fertilize your plants as needed. Avoid using water that has been chemically treated on edible plants, but save your water change leftovers for later use.

🌿 Want to learn more? This article is part of our complete Planted Tank & Aquascaping Guide. your ultimate resource for aquarium plants, aquascaping styles, substrates, and more.
March 24, 2024

Severum Tank Mates: My 15 Picks After Years in the Aquarium Trade

Severums have a well-earned reputation as gentle giants in the cichlid world. and having cared for them at local fish stores over the years, I’d say that’s accurate. They’re surprisingly peaceful for a cichlid of their size, which opens up a lot of stocking options. But you still need to choose carefully: the wrong tank mate can stress them out or end up as a meal. Here are my picks for the best severum tank mates, plus the ones I’d steer clear of.

Key Takeaways

Severums are fairly peaceful cichlids that can be kept with a variety of other tropical fish species.
The best severum cichlid tank mates are other medium to large fish that prefer a similar water temperature and parameters.
The severum cichlid is omnivorous, so they are not safe to keep with nano fish like neon tetras.
Severums will also eat live plants and invertebrates like shrimp.

The Top 15 Severum Tank Mates

Are you ready to meet 15 suitable tank mates for your severum cichlid? Read on to find the perfect match for your severum community! Here’s a video from our official Yo u Tube Channel. If you like our videos, subscribe to our channel.

Quick-Reference Comparison Table

Species	Adult Size	Min Tank	Ease	Compatibility
Silver Dollars	6 inches	75 gallons	7/10	High
Oscars	10-14 inches	75+ gallons	7/10	High
Dension Barbs	4 inches	55 gallons	7/10	High
Pearl Gourami	4-5 inches	30-40 gallons	7/10	High
Medium to large plecos	4 – 12 inches	Species-dependent, medium-sized species will thrive in a 55-gallon+ aquarium	7/10	High
Angelfish	6 inches	40 gallons	7/10	High
Blue Gourami	5-6 inches	35 gallons	7/10	High
Geophagus	5-12 inches	Species dependent, 55 gallons for smaller species	7/10	High
Larger Rainbowfish	4-6 inches	55 gallons	7/10	High
Uaru Cichlid	10-12 inches	75 gallons	7/10	High
Kissing Gourami	8-10 inches	50 gallons	7/10	High
Electric Blue Acara	6-7 inches	40 gallons	7/10	High
Salvini Cichlid	Up to 6 inches	55 gallons	7/10	High
Bolivian Rams	3 inches	30 gallons	7/10	High

1. Other Severums

Before we start getting into other species, let’s discuss the option of keeping multiple severums together in the same tank. Now, these fish don’t need to be kept in schools, and you can keep just a single fish, but many aquarists have kept them together without trouble.

Of course, severums are large fish, so you’ll probably need a tank that holds a few hundred gallons to keep a group into adulthood. Housing four or more fish together may also help to limit aggression.

They can be semi-aggressive toward each other, so it’s a good idea to buy them young and add them to the tank at the same time. Choosing individuals of different breeds may also help to prevent aggression, although you’ll probably want to prevent them from hybridizing if you are considering breeding them.

2. Silver Dollars

Ease: 7/10 — Good choice with a few conditions to watch.

Scientific name: Metynnis argenteus
Origin: South America
Adult size: 6 inches
Minimum tank size: 75 gallons
pH: 6-7
Temperature: 75-82°F
Temperament: Peaceful

The silver dollar is a peaceful South American schooling fish with an accurate name. These rounded fish are mostly silvery in color, although they may have some orange color on their anal fins.

Silver dollars tend to hang out in the middle and upper layers of the tank where their high activity levels add a lot of movement. However, these fish do best in groups of about 5 or more, so you’ll need a large aquarium to house them with your severums.

3. Oscars

Ease: 7/10 — Good choice with a few conditions to watch.

Scientific name: Astronotus ocellatus
Origin: South America
Adult size: 10-14 inches
Minimum tank size: 75+ gallons
pH: 6-7.5
Temperature: 68-82°F
Temperament: Semi-aggressive

Oscars can make great severum tank mates, although a lot depends on their individual personalities. Like the severum cichlid, these large South American cichlids are available in several awesome color patterns, and they generally get along well with tank mates that are too large to fit in their mouths!

Oscars are pretty easy to care for, although they are carnivorous fish that need a balanced diet that includes some meaty foods like earthworms. These fish also grow even larger than the severum cichlid, so this pairing will not work in anything less than a 75-gallon tank.

4. Dension Barbs

Ease: 7/10 — Good choice with a few conditions to watch.

Scientific name: Sahyadria denisonii
Origin: India
Adult size: 4 inches
Minimum tank size: 55 gallons
pH: 6.8-7.8
Temperature: 60-77°F
Temperament: Peaceful

The denison barb (also known as the roseline shark) is a great choice for aquarists who want a colorful active tank mate for their severum cichlid.

However, these fish prefer cooler water temperatures than many other tropical species, so you’d need to maintain your water temperatures around the mid-70s Fahrenheit to keep everyone comfortable. Denison barbs do best in a large school, so buy a group of at least 6 individuals.

5. Pearl Gourami

Ease: 7/10 — Good choice with a few conditions to watch.

Scientific name: Trichpodus leerii
Origin: Southeast Asia
Adult size: 4-5 inches
Minimum tank size: 30-40 gallons
pH: 6-7
Temperature: 75-82°F
Temperament: Peaceful

The pearl gourami is a peaceful, docile fish that enjoys similar water conditions to the severum cichlid. These tropical fish do well in community tanks, although you should keep four or more in the same tank.

These gouramis have a reddish body covered in beautiful pearly spots and a dark horizontal line from their eye to their tail. There pelvic fins are modified into interesting feelers that they move around to explore their environment, making this a fascinating fish to watch.

6. Medium to large plecos

Ease: 7/10 — Good choice with a few conditions to watch.

Scientific name: Hypostomus spp., Parancistrus spp., Ancistrus sp. etc.
Origin: South America
Adult size: 4 – 12 inches
Minimum tank size: Species-dependent, medium-sized species will thrive in a 55-gallon+ aquarium
pH: Neutral to slightly basic conditions are suitable for many species
Temperature: 75-80°F is suitable for many species
Temperament: Generally peaceful but can be territorial toward their own kind

Plecostomus catfish are laid-back bottom feeders that spend most of their time hanging out on the bottom of the tank or sucking onto rocks and driftwood. These cleaner fish are not aggressive, although they can hold their own against more boisterous tank mates.

Many species will make excellent tank mates for severums, although it’s important to research their needs carefully before you buy. Some pleco species grow surprisingly large, while others require strong water flow or high temperatures

Check out my guide to 15 pl e co fish species to learn about some of the best types in the hobby!

7. Angelfish

Ease: 7/10 — Good choice with a few conditions to watch.

Scientific name: Pterophyllum spp.
Origin: South America
Adult size: 6 inches
Minimum tank size: 40 gallons
pH: 6-7
Temperature: 75-82 °F
Temperament: Generally peaceful

Known for their distinctive body shape, freshwater angelfish are incredibly popular in the aquarium hobby. These medium-sized South American cichlids are good tank mates for severums and many other peaceful community fish.

Angelfish are available in a few different species, including the larger altum angelfish (Pterophyllum altum) and the rarer Leopold’s angelfish (P. leopoldi). The regular freshwater angelfish (P. scalare) is also available in many stunning color morphs.

8. Blue Gourami

Ease: 7/10 — Good choice with a few conditions to watch.

Scientific name: Trichopodus trichopterus
Origin: Southeast Asia
Adult size: 5-6 inches
Minimum tank size: 35 gallons
pH: 6-8
Temperature: 75-86°F
Temperament: Semi-aggressive

The blue gourami (also known as the three-spot gourami) is one of the most beautiful gourami species in the hobby, and it can make a good tank mate for severum cichlids.

However, blue gouramis are also one of the more aggressive gouramis, so you’ll need to consider the safety of any other tank mates you might want to keep.

9. Geophagus

Ease: 7/10 — Good choice with a few conditions to watch.

Scientific name: Geophagus spp.
Origin: Amazon River Basin, South America
Adult size: 5-12 inches
Minimum tank size: Species dependent, 55 gallons for smaller species
pH: Species dependent, slightly acidic to slightly basic
Temperature: Species dependent, generally upper 70s and lower 80s Fahrenheit
Temperament: Peaceful and social

Geophagus cichlids are also known as earth-eaters for their habit of searching for sucking in sand in search of food. This diverse group of South American cichlids includes many species that will work with severums, although it’s important to research the specific water parameter and tank size needs of each type before adding it to your tank.

It’s also important to house these fish in an aquarium with a sandy substrate to allow for natural foraging behaviors. The various geophagus cichlids inhabit diverse habitats, including still waters and fast-flowing rivers, so select species that will enjoy the same conditions as your severum cichlid.

10. Larger Rainbowfish

Ease: 7/10 — Good choice with a few conditions to watch.

Scientific name: Melanotaenia spp., Glossolepis etc.
Origin: Southeast Asia and Australasia
Adult size: 4-6 inches
Minimum tank size: 55 gallons
pH: 7-8
Temperature: 74-78°F
Temperament: Peaceful

Larger rainbowfish species, like the boesemani and red rainbowfish, can make excellent tank mates for severum cichlids, especially if you are looking for large and colorful species that swim actively in the open water.

However, it’s important to consider their water chemistry preferences when housing them with severum cichlids and South American species. These peaceful fish prefer temperatures in the mid-70s Fahrenheit and neutral to slightly basic water chemistry, so they have a fairly narrow parameter overlap with severums.

11. Uaru Cichlid

Ease: 7/10 — Good choice with a few conditions to watch.

Scientific name: Uaru amphiacanthoides
Origin: South America
Adult size: 10-12 inches
Minimum tank size: 75 gallons
pH: 6-7
Temperature: 82-86°F
Temperament: Peaceful

The Uaru is a large South American cichlid with attractive but neutral body colors. They are identified by the large black blotch on either side of their body and by their bright red or yellow eyes.

Uaru cichlids are very peaceful and make excellent severum cichlid tank mates, although they require pretty warm water. A tropical aquarium with temperatures in the lower 80s Fahrenheit will be ideal for this tank mate combination.

12. Kissing Gourami

Ease: 7/10 — Good choice with a few conditions to watch.

Scientific name: Helostoma temminkii
Origin: Southeast Asia
Adult size: 8-10 inches
Minimum tank size: 50 gallons
pH: 6-8
Temperature: 72-86°F
Temperament: Semi-aggressive

The kissing gourami is a fascinating freshwater species known for its habit of locking lips with its own kind. These filter-feeding fish are fairly peaceful, and their specialized diet means they can be kept with much smaller tank mates.

13. Electric Blue Acara

Ease: 7/10 — Good choice with a few conditions to watch.

Scientific name: Most likely to be a hybrid
Origin: South American ancestry
Adult size: 6-7 inches
Minimum tank size: 40 gallons
pH: 6-7
Temperature: 74-82°F
Temperament: Semi-aggressive

The electric blue acara is a stunning South American cichlid that is most likely to be a hybrid of two or more wild species. These medium-sized freshwater fish are excellent tankmates for severums because they show little aggression and thrive in the same water conditions.

🏆 My top pick: Out of all 15 options on this list, the Electric Blue Acara is the one I’d recommend first. The temperament match with severums is excellent. neither fish is looking for a fight. and their water parameter requirements line up well. A great pairing.

14. Salvini Cichlid

Ease: 7/10 — Good choice with a few conditions to watch.

View this post on Instagram

A post shared by OCEAN BEAUTY (@oceanbeauty.india)

Scientific name: Cichlasoma salvini
Origin: Central America from Mexico to Belize
Adult size: Up to 6 inches
Minimum tank size: 55 gallons
pH: 6.5-8
Temperature: 72-79°F
Temperament: Aggressive

The Salvini cichlid is one of the most gorgeous cichlid species in the aquarium world. Unfortunately, they tend to show aggressive breeding behavior, although large severums can generally hold their own against these stunning fish if you provide a suitable environment.

You can minimize aggressive behavior by keeping a single fish (salvini cichlid pairs can be highly aggressive), providing plenty of space in a large aquarium, and by providing plenty of caves and other hiding spots. Keep an eye on their behavior and be prepared to rehome them if you notice serious aggressive behavior.

15. Bolivian Rams

Ease: 7/10 — Good choice with a few conditions to watch.

Scientific name: Mikrogeophagus altispinosus
Origin: South America
Adult size: 3 inches
Minimum tank size: 30 gallons
pH: 6-7.5
Temperature: 75-82°F
Temperament: Peaceful

Bolivian rams are beautiful severum cichlid companions for more experienced fishkeepers. Just keep in mind that rams are dwarf cichlids, so it may be risky to add young specimens to a tank with full-grown severums that are large enough to swallow them!

Bolivian rams are generally very peaceful and tend to hang out at the bottom of the tank. These fish can also be kept in aquariums as small as 30 gallons, so it is possible to house several individuals in a larger tank.

Fish To Avoid

While severums get along with many other freshwater fish species, there are a few species that you should definitely avoid. Here are four tank mates that are not recommended for adult severum cichlids:

⚠️ The two mistakes I see most often: choosing fish that are too small (severums will bully or eat them once they’re fully grown) or too aggressive (severums are peaceful by cichlid standards and will get stressed by constant harassment). Size and temperament matching is everything with this species.

1. Dwarf Gourami

Large gouramis, like the pearl and kissing gouramis, are appropriate tank mates for severums, but smaller species, like honey and dwarf gouramis, are riskier. I would avoid keeping dwarf gouramis with larger cichlid species.

2. Smaller Tetras

Some fish keepers have success keeping severums with larger-bodied species like the black skirt tetra, although small schooling fish are generally not a good idea. You should definitely avoid small species like neon and ember tetras.

3. Highly aggressive fish

Despite their size, severum cichlids can be vulnerable to attacks from aggressive fish. It’s best to avoid highly aggressive species like wolf cichlids, although some fishkeepers have success with aggressive species like Jack Dempseys and the blood parrot cichlid.

Be prepared to rehome any fish that don’t get along with your severums as fights and aggressive behaviors can result in serious injuries for one or both fish.

4. African Cichlids

It’s generally a bad idea to mix African cichlids with severums. Rift Valley cichlids from East Africa require really hard, basic water to survive, while severums prefer neutral or even slightly acidic conditions.

Aggression and compatibility can also be a problem, so if you do try this pairing, stick to more peaceful species like electric yellow labs.

Care Basics

Also known as banded cichlids or ‘poor man’s discus,’ the severum cichlid (Heros sp.) is a large but peaceful South American fish from the cichlid family. There are many different varieties in the aquarium trade, including the green severum, the gold severum, and various other species in the Heros genus.

Severums can grow to about a foot long out in the wild, but they usually max out at less than ten inches in the home aquarium. They are easy to care for, although they require a large aquarium of at least 55 gallons.

Diet

Severums are omnivorous fish that require a varied diet. High-quality pellets are a good staple diet but you should include frozen foods like brine shrimp, bloodworms, and plant matter like blanched vegetables to keep your fish healthy and encourage breeding behavior.

Recommended Water Parameters

Temperature: 75-84°F
pH: 6-7.5
Water hardness: 4-6dH

There’s much more to learn about severum cichlid care! Go ahead and check out my in-depth severum cichlid care guide for much more on these awesome fish.

Community Aquarium Setup Tips

Aquarium Size

A 55-gallon tank is suitable for growing out young fish or keeping a single severum cichlid. However, larger fish will do better in a 75-gallon tank, and you’ll need even more space if you’re adding a few tank mates.

Great Beginner SW Tank

Aqueon 60 Gallon Breeder

This new 60 gallon breeder by Aqueon has the length and width of a 75 gallon tank, but at a shorter height. This is the most economical and effective 4 foot gallon tank for the saltwater hobby now.

Buy on Petco

A 125+ gallon setup should provide adequate space for a severum cichlid community with a few other medium/large fish, although a bigger tank is always better!

Decor and Planting

The ideal layout for the severum cichlid includes plenty of driftwood over a sandy substrate. Unfortunately, these omnivorous cichlids will eat live plants, so it’s generally not a good idea to keep these partly vegetarian fish in planted tanks. However, you could try some tough species like Java fern if you’re not too worried about them getting chewed on.

Characteristics of Suitable Companion species

This species can be housed with many other medium to large freshwater aquarium fish. However, it’s important to select tank mates that thrive in the same water conditions as the severum cichlid.

Severums are not particularly aggressive, although they can hold their own with slightly more aggressive and boisterous species. Small, slow-moving fish are a risky choice because severums are omnivorous.

How big of a tank do Severums need?

The minimum tank size for severum cichlids is 55 gallons. However, breeding pairs will require a 75-gallon tank, and you may need to go even larger when keeping multiple fish or adding a few medium to large tank mates.

Are Severums aggressive?

Severums are relatively peaceful cichlids, making them an excellent choice for a larger community tank. However, some species are more aggressive than others and each specimen has its own personality.

They may also become aggressive when breeding, so these fish are generally classified as semi-aggressive.

Will Severums eat neon tetras?

Severums are omnivorous and generally feed on plant material and invertebrates. However, a larger specimen will feed on other fish if they are slow enough to catch and small enough to swallow. Keeping the severum cichlid with neon tetras and other small schooling species is not recommended.

Can you keep a single Severum?

Severums can be kept on their own or in small groups. Some sources indicate that single fish may become more aggressive without the company of their own kind, although many aquarists have no problems keeping these fish on their own.

Can a severum live with African cichlids?

Severums are not ideal tank mates for African cichlids from Lake Malawi, Victoria, and Tanganyika. Those fish are adapted to water with high pH and mineral content, whereas severums prefer soft water with a pH closer to neutral.

South and Central American cichlid species or West African cichlids like the kribensis are usually a better match on water parameters.

Expert Take

Severums are one of the most underrated cichlids in the hobby. They’re big, personable, and surprisingly peaceful for a cichlid their size — unless they’re breeding, at which point the entire tank becomes off-limits to other fish. The real compatibility challenge isn’t aggression, it’s size. Severums reach 8–10 inches (20–25 cm), and most ‘peaceful’ small fish simply disappear into them over time. — Mark Valderrama, AquariumStoreDepot

Hard Rule: Never add fish under 4 inches (10 cm) to a severum tank. A 10-inch severum doesn’t need to be aggressive to eat a tetra — it’s just what happens. Keep companions at a minimum of half the severum’s body length.

Mark’s Pick: Large, peaceful cichlids or bottom dwellers — large plecos, geophagus, or festivum cichlids. These fish share the severum’s water preferences and can hold their own as the severum grows.

Who Is This Setup Right For?

Good Fit If:

You have a 75+ gallon tank for a pair, 55 gallons for a solo severum
You keep large, hardy fish that won’t be intimidated or eaten as the severum matures
You enjoy large cichlids with real personality and aren’t put off by breeding aggression
You keep South American biotope conditions — pH 6.0–7.5, moderate hardness

Avoid If:

You have small fish under 4 inches (10 cm) — they will be eaten as the severum grows
You want to pair severums in anything under 75 gallons — breeding aggression requires space
You keep delicate, nervous fish that don’t handle the presence of large cichlids well
You want a peaceful community without any cichlid-level territorial behavior during breeding season

Final Thoughts

Careful consideration is necessary when choosing tank mates for freshwater fish – especially when cichlids are involved. Fortunately, the severum cichlid is a gentle giant of the fish keeping world, suitable for many different freshwater tank mates. I hope this guide to the 15 best severum cichlid tank mates has helped you narrow down your options and find the perfect companions for your severum!

Do you keep severums? Share your favorite tank mates in the comments below!

📘 Want to learn more? This article is part of our complete Freshwater Fish Guide. your ultimate resource for freshwater species, care tips, tank setup, and more.

March 23, 2024

Fish Tank Filter Not Working? My Troubleshooting Guide After 25 Years
Is your fish tank filter not working?

Aquarium filters are essential in this hobby, so when they stop working, you can expect some problems! But what should you do if your filter malfunctions? Well, don’t rush off to buy a new one too soon because there’s a good chance you can fix it yourself!

In this guide, I’m going to help you get your aquarium filter up and running again. We’ll start off with some pretty obvious stuff and progress to more technical issues, so read through until the end and you should have the solution you need.
Key Takeaways
- Aquarium filters can stop working for many different reasons, but it’s often possible to fix the problem at home.
- Start with the simplest solutions before taking drastic actions. Sometimes all you need to do is check your filter’s electrical plug.
- A lack of aquarium maintenance can cause various filter problems, so invest a little time every week or two to inspect and maintain your equipment.
- ELECTRICITY IS DANGEROUS. Unplug your filter before inspecting it and please leave electrical work to competent individuals.
Troubleshooting – First Steps and Clues

Are you sure it’s not working?

This may seem like a silly question, but some filters are almost completely silent so you really need to look or feel to know if they’re running. Look for water flow near the filter’s outflow to know if water is moving through the pump.

If you’re sure your filter is not running, it’s time to figure out why.

When did it stop working?

Doing a little detective work can help you figure out some potential causes of your fish tank filter not working.

Let’s take a look at a few scenarios:
- After a power outage: Some filters need to be primed each time you start them. So, if your power went out, you might be able to re-prime your filter and get it up and running again.
- After a power surge: Lightning strikes, tree falls, and power outages can all cause surges that could damage electrical equipment¹.
- Gradual loss of performance: If your filter has been weak or noisy for some time, it could be a sign of a clogged impeller or filter media. These problems tend to build up over time.
Fish Tank Filter Not Working – 5 Possible Causes

Finding the problem with your aquarium filtration system is much easier when you know where to look. Continue reading to discover five possible causes and what you can do to solve them.

1. Power Problems

Aquarium filters need electricity to run, so that’s the first place to look when your fish tank filter stops working. Before we go any further, I just want to remind you of something obvious: ELECTRICITY IS DANGEROUS. Please leave electrical work to trained professionals.

With that out of the way, let’s look at some safe tests that you can do.
- Check the power source
If your filter isn’t running at all, don’t be too quick to assume that the filter is the problem! The issue could also lie with your power supply, power strip, or any of the connections between your electrical panel and the filter itself.

Start by making sure the filter is plugged in at a power outlet. Some outlets have a dedicated on/off switch, so make sure that’s in the ‘on’ position.

If it’s definitely plugged in but still not running, your next step is to test the outlet. You can do this by unplugging the filter and plugging in a different electrical appliance like a lamp. If that doesn’t work either, your filter is probably not the problem.
- Check your power strip
Sometimes there’s nothing wrong with the power source or the filter. Your powerstrip might be faulty or need to be reset. Some power strips include a reset button that will need to be pressed after a power surge or overload.
- Inspect the cable
Electrical cables are pretty prone to damage, so it’s a good idea to visually inspect them for signs of wear or breaks. If you’re handy, you may be able to repair a worn cable yourself, but I recommend getting help from a pro if you’re not sure.
- Are you using a timer?
It’s best to set your aquarium lights on a timer to keep a regular day/night schedule. However, your fish tank filter should be set to run constantly.

It’s annoyingly easy to get your plugs mixed up during the aquarium cleaning process, and sometimes the solution is as simple as switching plugs! If this happens to you, consider putting a zip tie or some colored tape on your filter cable to help you identify it easily.

2. Clogged Filter

Your filter is designed to collect debris from the water, but sometimes, these waste particles build up to such an extent that they create blockages that prevent your filter from working properly.
- Rinse regularly
Many fish tank filters use a synthetic sponge material as a filtration media. These sponges do not need to be replaced until they begin to fall apart, although they do require regular maintenance to avoid blockages.

The dirt that collects in your aquarium filter media will reduce water flow and mechanical filtration, but you can avoid this by simply rinsing the sponge outside of your aquarium in some tank water. Avoid using chemicals or hot water when cleaning your sponge media as this can kill the good bacteria that are essential for proper filtration.

Check out my detailed guide to the aquarium cycle to learn more about beneficial bacteria and the nitrogen cycle.
- When to replace
Some filters are designed to use cartridges that must be replaced regularly. This type of media should be replaced at the intervals recommended by the manufacturer to avoid a reduced water flow rate. Filter floss is another filter media that clogs easily and will need to be replaced regularly.

3. Air Locks

Sometimes, air gets into the filter and causes an air lock which reduces your flow rate or even prevents your filter from moving water. This often happens when the filter intake is not positioned below the water’s surface, although it also occurs if you run an airstone near the intake. You may need to prime your filter to get it restarted, although the procedure will differ depending on the type of filter you have.
- Hang on back filters
Many hang-on-back (HOB) filters need to be primed before they can operate or they may be very noisy and fail to operate correctly. However, some models have self-priming technology.

To prime a HOB, simply fill the impeller chamber with water from the aquarium until it begins to flow through the outflow and back into the tank. Then, you can adjust the flow rate to suit your needs.
- Canister filters
Many canister filters have self-priming technology, but some must be manually primed using the built-in pump. You may also need to rock your canister filter back and forth or side to side to dislodge any air trapped in the impeller housing. These filters should be placed below your aquarium for best results.

4. Disrupted Water Flow

Each aquarium filter type works differently, but they are all designed to suck water from the aquarium and pass it through some sort of filter media. The obvious exceptions are sponge or under gravel filters that work with an air pump.

Your filtration system will not work properly if water can’t flow through the media as it should, so it’s important to inspect your filter and ensure that everything is clean and put together properly.
- Water intake obstructions
The water intake is a common source of problems since this is the first place where blockages can occur. Inspect the intake grid or tubes for obstructions like plant leaves or hiding snails.

Sometimes, the intake tube of your filter may become dislodged, which disrupts the flow of water through the system. Make sure this component is seated properly as it can make a huge difference.
- Flow valves and flow rate adjustment
Many modern aquarium filters come with an adjustable flow rate, so this is a good place to start if your filter just seems a little weak. Check out your user manual or look for a dial or lever to increase the flow rate.

Canister filters have valves on both the intake and output valves. Water will not be able to flow through the canister if either of these valves are shut, so make sure the tabs of each valve are in the open position, or at least open enough for water to pass through.
- Water level in the tank
Over time, water will evaporate from your aquarium, leading to a slow decrease in water level. If the level gets below your filter’s intake, the unit will begin to suck air, and it may overheat or malfunction. Keep your aquarium full with regular top-ups and water changes.

5. Filter Motor Problems
- Clogged impeller
Internal power filters, canister filters, and hang-on-back filters all have a part known as an impeller, and this is a very common cause of filter issues.

The filter impeller is the part of the pump that spins, creating a water current that sucks water through the filtration media and back into the tank. Sometimes, this crucial part becomes dislodged from its correct position or it may get clogged with gravel or wrapped up in fibers or hairs that prevent it from spinning.
- Impeller maintenance
You can usually access the impeller pretty easily without any special tools, but make sure the filter is unplugged before opening it up. Gently remove the impeller with your fingers or a pair of tweezers and clean it off, paying attention to the blades and the steel impeller shaft. You should also look for obstructions in the impeller housing and clean it out if necessary.
- Impeller replacement
You can often get your aquarium filter back up and running by simply cleaning out the impeller and housing, but eventually, you might need to replace some parts. Impellers don’t last forever, so order a replacement when yours becomes grooved, worn, or broken.

What To Do If You Can’t Fix It – 5 Helpful Tips

You’re going to need to take action if you’ve tried all the options listed above and you still can’t get your filter to run. Here’s what you should do:
- Aerate your aquarium water
Your aquarium is not going to crash instantly without a filter, although the situation can become more serious after a few hours.

In the meantime, use an air pump and air stone to oxygenate your aquarium water. This will help your fish breathe and supply dissolved oxygen to the beneficial bacteria that live within your substrate and on surfaces within the tank.
- Run a spare filter
I recommend keeping a cheap spare filter for this kind of situation, but it’s very important to use it correctly here. If you’ve got an idea of how aquarium cycling and the nitrogen cycle work, you’ll know that special bacteria live in the media in your filter and that it can take several weeks to build up a decent colony.

Put the media from your faulty filter into your spare until you can get a new filter or fit replacement parts. You may have to trim the old sponge down to size, but that shouldn’t be a problem. Bio balls and other media types can also be transferred to your spare filter if the design allows custom media.
- Buying replacement parts
You can usually buy replacement parts if you have a decent brand-name fish tank filter, although it may make more sense to buy a new filter in some cases. You can ask your local fish store to order replacement parts or simply purchase them online.
- What if you don’t have a spare filter?
It is possible to care for the beneficial bacteria in your old filter media, although it can get a little messy if the old media hasn’t been rinsed in a while. Gently remove the media and place it in the tank near an air stone to encourage some water movement through the media and keep the good bacteria oxygenated until you can get a new filter up and running.

Note that if you purchase the same filter to replace your broken one, you can swap the filter media into the new filter. This will help prevent losses in the bacteria colony as the colony will still function in the new filter.
- Running a second filter
Did you know that you can run two or even three filters in the same aquarium? Most aquarists will run a single powerful filter, although two smaller fish tank filters can provide adequate filtration while giving you that extra insurance in case one fails.

Understocking your tank and growing live plants are great ways to slow the build-up of nitrate levels in the long run, but you can also reduce your filtration needs by feeding your fish correctly. Uneaten food is a major cause of poor water quality.

Why isn’t my fish tank water filter working?

Fish tank filters don’t last forever, although you should get many years of use out of a quality product. The most common problems that affect aquarium filters are air locks, clogged media, clogged impellers, and power supply problems.

How do I know if my fish tank filter is broken?

Some fish tank filters are virtually silent, but all canister, hang on back, and internal power filters should create some flow from their outlet. Your filter is not working if it does not pump any water.

How do you unclog a fish tank filter?

Start by rinsing out your filtration media. I recommend rinsing your filter sponge and media in a separate container filled with aquarium water from a water change.

Some filter cartridges and floss cannot be reused once clogged, so remember to replace them on a regular basis. Your filter may have indicators that tell you when to service or replace media, but you can also look for guidance in your instruction manual or check with the manufacturer online.

How long can fish survive without a filter?

Your fish may survive hours, days, or weeks without a filter. it all depends on your aquarium size, fish species, stocking level, and water chemistry. You can keep your water safer for longer by running an airstone, reducing feeding, and by testing water parameters and performing water changes as necessary.

What to do if your fish filter stops working?

A malfunctioning filter will reduce water quality, so this is one problem you should attend to immediately. Take a few minutes to run through the solutions mentioned in this article, including checking the power supply and looking for obstructions and clogs.

If you can’t solve the problem, you’ll need to install a different filter. I recommend seeding the new filter media with bacteria from your old filter.

How do I know if my filter is working in my fish tank?

Adequate mechanical and biological filtration will keep your water clean and prevent odors. A working fish tank filter will suck water into its outtake tube and pump it back into the aquarium. This should create a gentle current that you can see, hear, or feel in the water.

Final Thoughts

Providing proper filtration is essential for maintaining a beautiful aquarium and healthy fish, so it can be pretty stressful when your equipment malfunctions. I hope the advice in this guide helps you fix your filter problems without ordering a replacement, but please keep safety in mind when inspecting electrical equipment.

🔧 Want to learn more? This article is part of our complete Aquarium Equipment & Gear Guide. your ultimate resource for filters, heaters, lights, pumps, tanks, and more.
March 17, 2024
Best Beginner Tropical Fish: My 11 Picks After 25 Years of Fishkeeping
I’ve been keeping tropical fish for over 25 years, and choosing the right beginner fish is something I feel strongly about. Most people walk into a pet store, pick something colorful, and end up with incompatible fish or species that outgrow their tank within a year. After keeping hundreds of species across freshwater setups. from 5-gallon betta tanks to 125-gallon community builds. I’ve put together this list of 11 fish I’d genuinely recommend to any first-time fish keeper.
Key Takeaways
- The best tropical fish for beginners are small, peaceful species that can adapt to various water conditions and store-bought foods.
- Tropical fish require warm, filtered water for long-term care. Select a filter and heater suitable for your tank size.
- Measure your local water parameters before selecting your first fish. This will help you choose fish that will suit your conditions.
- Read up on the aquarium cycle and water quality maintenance before buying your first fish. It’s generally safer for first-time fish keepers to cycle their aquarium before adding fish.
Best Beginner Tropical Fish

1. Livebearers
- Scientific name: Poecilia and Xiphophorus spp.
- Origin: North, Central, and South America
- Size: 1 – 6 inches
- Minimum tank size: 10 gallons for guppies and Endler’s, 20+ gallons for swordtails and molly fish
- Temperament: Generally peaceful
- Swimming level: All levels
- pH: Most species prefer pH levels above 7
- Temperature: Upper 60’s to upper 70’s Fahrenheit
- Key benefits: Affordable, colorful, easy to breed
Livebearers are a great first-fish because they are so affordable and easy to care for. These fish are also available in a wide variety of colors, from jet-black molly fish to fiery red variable platies and multicolored fancy guppies, so you can choose literally any color you like!

Of all the livebearers, my personal preference is platies. Guppies and mollies have been so heavily overbred that many store-bought specimens are weaker and more disease-prone than they should be. Platies have held up much better. they’re genuinely hardier, healthier, and still come in a great range of colors. If you’re choosing a livebearer for your first tank, start with platies.

Several differnet species from the same family are available in the hobby, including:
- Guppy fish (Poecilia reticulata)
- Endler’s livebearer (Poecilia wingei)
- Platy fish (Xiphophorus maculatus & X. variatus)
- Molly fish (Poecilia sphenops & P. latipinna)
- Swordtail fish (Xiphophorus hellerii).
All of these tropical fish are members of the Poeciliidae, a family known for producing live baby fry rather than laying eggs. This makes livebearers very easy to breed, even for complete beginners. However, you could keep only males if you don’t want your fish to multiply¹.

Live-bearing fish are generally very easy to care for and will thrive on a diet of small pellets or flake food. Some species will even feed on algae and help to keep their own tank clean!

2. Betta

WYSIWYG Available!

Betta Fish

Use Coupon Code ASDFISH at Checkout
Betta Fish are one of the most beautiful varieties of freshwater fish available in the hobby. Easy to care for with plenty of varieties!

Buy Premium Varieties Buy On Petco Online
- Scientific name: Betta splendens
- Origin: Thailand
- Size: 2- 2.5 inches
- Minimum tank size: 5+ gallons
- Temperament: Aggressive
- Swimming level: Middle and upper levels
- pH: 6.5-8
- Temperature: 76-81°F
- Key benefits: Spectacular colors and fins, thrives in tanks as small as 5 gallons
The betta fish is one of the most popular fish in the hobby due to their beauty and feisty personality. The combination of amazing colors and impressive flowing fins make these small fish excellent display animals for small aquariums.

Bettas are suitable for some community tanks, although they are usually kept alone in their own tank. These fish don’t need a lot of room, and it’s possible to keep them happy and healthy in a tank as small as 5 gallons. However, you will need to perform regular water changes and equip your aquarium with an aquarium heater and a suitable filter.

One strong recommendation if you’re buying a betta: look for a Plakat (short-fin betta). Long-finned varieties are beautiful, but their fins are so heavy they can barely swim and they’re prone to fin rot. Plakats are what bettas look like in the wild. they swim powerfully, tend to be healthier, and are noticeably more active fish. Many hobbyists who switch to Plakats never go back to long-finned varieties.

3. Danios

Glowlight Danio Near Gravel” class=”wp-image-557066″/>
- Scientific name: Danio rerio
- Origin: Asia
- Size: 2-2.5 inches
- Minimum tank size: gallons
- Temperament: Peaceful
- Swimming level: All levels
- pH: 6.5-7
- Temperature: 72-81°F
- Key benefits: Hardy, affordable, and active. Various breeds available
There are many danio species in the fishkeeping hobby, and some of them are excellent options for beginners. The popular zebra danio (Danio rerio) is one of the hardiest species and is suitable for larger aquariums in the 20-gallon range.

Zebra d anios usually have a silvery body with dark horizontal stripes. However, there are many different breeds, and the spotted leopard danios and the eye-catching neon Glofish breeds are all the same species.

These active fish can be kept in tanks as small as 10 gallons, although they will appreciate the extra swimming space of a 20-gallon long. Smaller species like the celestial pearl danio are a little more difficult to care for, although they are suitable for moderately experienced fishkeepers with a planted aquarium.

4. Corydoras Catfish

Habrosus Cory Catfish

A small and active cory catfish. Does best in groups of at least 5

Click For Best Price
- Scientific name: Corydoras spp.
- Origin: South America
- Size: 1-3 inches
- Minimum tank size: usually 30+ gallons, although small species can be kept in tanks as small as 10 gallons
- Temperament: Peaceful
- Swimming level: Mostly bottom dwellers
- pH: 6.5-8
- Temperature: 72-82°F depending on species
- Key benefits: Peaceful community fish for the bottom levels of tropical aquariums
There are dozens of corydoras species available in the aquarium hobby, including popular species like the peppered, bronze, albino, and panda cory catfish. These chunky bottom feeders are some of the best tropical fish for community tanks, although they don’t win any prizes for their color.

Cory catfish prefer to spend their time peacefully searching the substrate for tasty morsels, although they often shoot up to the surface to grab a breath of air. These entertaining fish will hang out in loose schools of their own species, so try to buy a small group of a single type.

My personal favorite corydoras for beginners is the Sterbai cory. It’s one of the most striking in the family. cream-colored spots on a dark body with orange-tipped pectoral fins. and importantly, it’s a warmer-water species that thrives at the higher temperatures most tropical community tanks run. I’ve kept Sterbai corys across multiple tank setups and they never disappoint.

5. Honey Gourami

Honey Gourami

One of the more peaceful Gourami fish available in the hobby. Has a unique yellow coloration and only grows up to 2 inches in length

Click For Best Price
- Scientific name: Trichogaster chuna
- Origin: Southern Asia
- Size: 2-2.5 inches
- Minimum tank size: 10 gallons
- Temperament: Peaceful
- Swimming level: Middle and upper levels
- pH: 6-8
- Temperature: 74-82°F
- Key benefits: Peaceful alternative to betta fish
The honey gourami is a peaceful labyrinth fish that can be kept with other popular tropical fish like neon tetras, rainbow fish, and many more. These interesting fish have modified pelvic fins that they use like little arms to feel the world around them.

Honey gouramis aren’t quite as colorful as dwarf gouramis, although they are much better fish for beginners due to their peaceful nature. However, these fish are also available in some great color morphs like the sunset and red breeds.

Honey gouramis are predators that hunt for small aquatic invertebrates and their larvae, although they are easy to feed in captivity. Provide regular flake food and some tasty treats like frozen blood worms and brine shrimp.

7. Cherry Barb

Cherry Barb

A popular freshwater fish from the barb family. One of the most peaceful barb fish

Click For Best Price
- Scientific name: Puntius titteya
- Origin: Sri Lanka, South Asia
- Size: 2 inches
- Minimum tank size: 15-20 gallons
- Temperament: Peaceful
- Swimming level: All levels
- pH: 6-7.5
- Temperature: 73-81°F
- Key benefits: A peaceful and inexpensive schooling barb
Cherry barbs are peaceful schooling fish that can be kept with other small peaceful fish like white cloud minnows and zebra danios.

Males develop a beautiful cherry red shade, although females are also attractive, with a rich orange color and a pair of bright and dark horizontal stripes on each side.

Cherry barbs are omnivorous fish that thrive on small pellets or flake foods, although they will appreciate a varied diet including live or frozen foods like blood worms. These fish love to hang out together so pick up a school of six or more.

8. Black Neon Tetra

Black Neon Tetra

A variant neon variety. More reliant than neon and cardinal tetras

Click For Best Price Buy From Petco Online
- Scientific name: Hyphessobrycon herbertaxelrodi
- Origin: South America
- Size: 1.5 inches
- Minimum tank size: 15-20 gallons
- Temperament: Peaceful
- Swimming level: Middle and upper levels
- pH: 5.5-7.5
- Temperature: 71-82°F
- Key benefits: One of the hardiest tetras
Black neon tetras are perfect community fish for beginners, offering great color and a peaceful nature. These midwater swimming fish will thrive in a tropical fish tank with other schooling fish and bottom dwellers like corydoras catfish and the bristlenose pleco.

Black neon tetras are schooling fish that should be kept in a group of their own species. A 15-gallon tank would be suitable for about 6 fish.

9. Small Plecos
- Scientific name: Ancistrus spp. etc.
- Origin: South America
- Size: 4-6 inches
- Minimum tank size: 20-30 gallons
- Temperament: Peaceful
- Swimming level: Bottom dweller
- pH: 5.7-7.5
- Temperature: 73-80°F
- Key benefits: Fascinating bottom dwellers that can help to control algae in the aquarium
There are hundreds of pleco species known in the aquarium trade, although small species like the bristlenose pleco are most suitable for beginner fish keepers. These fascinating creatures are very peaceful despite their unusual appearance.

These gentle catfish will not bother other fish, although they can be a little territorial toward their own kind. That means it’s best to keep just one small pleco species in the same aquarium unless you have a large tank.

Bristlenose and other small plecos are herbivores that can do a great job of cleaning algae in the aquarium, although you should also provide plenty of driftwood for them to graze on. They will also eat plant food like cucumber, zucchini, sinking algae wafers, and gel foods.

10. Kuhli Loach

Kuhli Loach

Kuhli Loaches are hardy bottom-dwelling fish. Nocturnal in nature. Gets along with many fish and tolerate of coldwater environments

Click For Best Price
- Scientific name: Pangio kuhlii
- Origin: Southeast Asia
- Size: 3-4 inches
- Minimum tank size: 20 gallons
- Temperament: Peaceful
- Swimming level: Bottom dweller
- pH: 5.5-6.5
- Temperature: 73-86°F
- Key benefits: Interesting bottom dweller that will clean up uneaten food
Kuhli loaches are fascinating creatures that look like hyperactive eels as they zoom along the bottom of the tank. However, these small loaches are mostly nocturnal, so they are usually active after the lights go off.

There are a few species in the hobby including the black kuhli loach which is really more of a chocolate-brown shade. However, the regular banded kuhli loach is one of the most attractive types.

These fish love to hang out with their own kind, so it’s best to buy five or more and let them explore together. They will burrow under rocks and driftwood or tunnel into the substrate but come out to search for uneaten food and sinking pellets or tablets when they smell food in the water.

11. Kribensis Cichlid
- Scientific name: Pelvicachromis pulcher
- Origin: West Africa
- Size: 3-4 inches
- Minimum tank size: 20 gallons
- Temperament: Generally peaceful but can be aggressive when breeding
- Swimming level: All levels
- pH: 6-7
- Temperature: 75-79°F
- Key benefits: A relatively peaceful and adaptable African cichlid with amazing colors
The kribensis cichlid is a beautiful dwarf cichlid from West African rivers. These colorful fish do not require the hard, high pH water chemistry of other popular African cichlids, making them a good choice for many community setups or even breeding projects.

These fish spawn easily, and they are fascinating to breed, although they can get pretty aggressive in the breeding season. Males and females are similar in appearance, although females tend to be shorter and plumper, while males have a more streamlined body shape and longer pointed caudal, anal and dorsal fins.

Kribensis cichlids are easy to care for and will thrive on regular commercial foods like flakes and pellets. They are generally suitable for larger planted tropical fish tanks with other small, peaceful fish, although they are not shrimp-safe.

Species to Avoid

Unfortunately, there are many popular tropical fish that are not really suitable for beginner fish owners. Most pet stores have knowledgeable staff that will point new fishkeepers in the right direction, although sometimes beginners buy fish that are better left to the experts.

Avoid these fish until you are a little more experienced.

The most common impulse buy I see beginners make is goldfish. Despite being sold in small tanks at the pet store, fancy goldfish can reach 8. 12 inches and single-tailed varieties can hit 12. 18 inches. They’re cold-water fish that don’t belong in a tropical setup, produce significantly more waste than most species, and need far more filtration than beginners typically run. Goldfish are not beginner fish. they’re a dedicated hobby in themselves.

Tankbusters

Some popular aquarium fish grow surprisingly large and require very large aquariums when they reach adult size. Avoid these common tank busters until you are more experienced and have room for a much larger tank:
- Common pleco – grows to over 12 inches
- Red-tailed catfish – grows to over 5 feet!
- Bala sh ark – grows to over 12 inches
- Clown loach – grows to about 12 inches
- Tinfoil barb – grows to over 12 inches
Aggressive Species

Some aquarium fish are prized for their aggressive behaviors, while others are surprisingly mean and territorial. Aggressive fish can be exciting pets, although they are not recommended for beginners.

Let’s take a look at some examples.
- Chinese algae-eater – These fish are known to feed on the slime coat of other fish
- Red-tailed and rainbow sharks – These fish can be surprisingly aggressive and territorial, especially toward their own kind.
- Jaguar Cichlid – These large cichlids are extremely aggressive towards other fish and may even bite human hands.
- Red devil cichlid – Red devils are highly aggressive Central American Cichlids that need large aquariums and tough tank mates.
Species With Special Water or Care Requirements

Some freshwater fish breeds and species have specific needs that make them more difficult to care for. The following fish are better for more experienced fish keepers.
- Fancy goldfish – Goldfish are not tropical fish. These common aquarium fish need cool water conditions and are usually kept in unheated fish tanks.
- African cichlids – African cichlids from the Rift Valley lakes require high pH water with a high mineral content. Many species are highly territorial too, so these fish are better left to more experienced fishkeepers.
- Discus – The discus fish requires pristine water conditions to survive. These sensitive fish are not suitable for beginners.
Why Are Some Species Easier To Keep?

Betta Fish” class=”wp-image-543292″/>

You may be wondering how I chose the fish in this list, or why some fish are better for beginners than others. Well, it really comes down to a few different factors that make them tougher and easier to care for.

Let’s take a look at five important characteristics of good beginner fish.
- Hardiness
The ideal beginner fish are relatively hardy and will usually survive the kind of mistakes inexperienced fish keepers tend to make.

Many new fish keepers will take some time to figure out how much to feed their fish, or how often to clean their tank or change their water. Basically, hardy beginner fish are much harder to kill.
- Diet
Some fish species have very specific diets that are difficult to provide in an aquarium. Fortunately, all the fish in this list will feed on regular commercial foods like flakes, pellets, or wafers.

However, it’s still important to select the right kinds of foods for your specific fish species. Many small schooling fish will do well on a flake diet, while bottom feeders like corydoras prefer sinking pellets and tablets.
- Size
Bigger fish aren’t necesarily more difficult to care for, although small fish in the 1.5-3 inch range make ideal beginner fish because they tend to do well in the smaller aquariums that most fish keepers start out with.

Aquariums in the 15 to 30-gallon range are generally cheaper and easier for beginners to maintain.
- Temperament
Each fish has its own individual temperament, although different species tend to have certain characteristics. Confident but peaceful fish are the ideal species for beginners because they tend to feed well and get along with other species. Aggressive and shy fish may require more experience.
- Adaptability
Some fish have very specific requirements when it comes to temperature, water chemistry, flow, and other factors.

These fish may be easy to care for if you can provide these conditions, but it is usually best to start out with adaptable fish that thrive in the average home aquarium.

Aquarium Basics – Getting Started

Have you chosen your favorite beginner fish? Run through this list of basic equipment and important concepts before you buy your first fish.

Basic Equipment List
- Suitable fish tank – A 15-30 gallon is ideal for beginner fish keepers as they are relatively easy to maintain. Avoid bowls or tanks smaller than 5 gallons.
- Aquarium heater and thermometer – Tropical fish require a suitable heater to create the warm water conditions that match their natural habitat.
- Aquarium filter – You will need a filter to keep your water clean and clear. An air-powered sponge filter is adequate for a small aquarium, although power filters, hang-on-backs, and canister filters are better for larger aquariums.
- Substrate and decorations – Use only clean, aquarium safe products in your fish tank.
- Maintenance equipment – You’ll also need some cleaning and maintenance equipment like a gravel vacuum, water test kit (pH, GH, KH, Ammonia, Nitrite, Nitrate), water conditioner and a bucket.
Important Concepts for Beginners

Take the time to learn about the following important concepts before you buy your first fish.
- Water parameters – Its important to measure your water hardness and pH before buying your fisrt fish. That way you can choose fish that are naturally suited to your water conditions.
- The Nitrogen Cycle – Excess nutrients from fish waste and uneaten food are processed by special bacteria in a cycled aquarium. Understanding this cycle will make you a better fish keeper and help you maintain a healthy aquarium.
- Regular Maintenance – Your aquarium will require regular cleaning and partial water changes to remove dirt, algae, and the excess nutrients left behind from the nitrogen cycle. Ideally, the frequency of these water changes should be based on nitrate levels measured with your water test kit.
Some of these concepts may seem a little tricky at first, but don’t be intimidated by the technical side of the hobby. The Aquarium Store Depot website is full of in-depth articles that will help you keep your tropical fish happy and healthy for years to come!

FAQs

What is the easiest tropical fish to keep for beginners?

Guppies and zebra danios are among the easiest tropical fish in the aquarium hobby. Zebra danios are particularly hardy fish, although they do best in a larger aquarium of 20 gallons or more. Guppies will thrive in a tank of 10-15 gallons with basic care.

What is the best tropical fish for a new tank?

Many new fish keepers make the mistake of adding fish to a new tank right away because they are unaware of the aquarium nitrogen cycle. This process can take several weeks, although some aquarists successfully cycle new aquariums with hardy fish like zebra danios.

What fish to put in tank first?

Its best to add just a few fish at a time until your biological filtration system is fully accustomed to a high bioload. Hardy schooling fish like zebra danios or black neon tetras are a good first fish, although there is no set sequence when adding fish to an aquarium.

Final Thoughts

Choosing your first fish is an exciting step at the start of a wonderful new hobby and hope the information in this guide has helped you choose your next pets! My best advice is to take your time and enjoy the process of learning before buying your first fish.

Looking for more fishkeeping information? Browse the rest of my in depth articles for more on these and other tropical freshwater fish. You’ll also find loads of other helpful articles on every aspect of tropical fishkeeping!

📘 Want to learn more? This article is part of our complete Freshwater Fish Guide. your ultimate resource for freshwater species, care tips, tank setup, and more.

🐟 Want to learn more? This article is part of our complete Aquarium Care Guide. your ultimate resource for water chemistry, maintenance, feeding, disease prevention, and everything you need for a healthy tank.
March 16, 2024
Feeder Fish: My Honest Take After 25 Years of Using Them
I’ve used feeder fish in my own tanks over the years. mainly feeder guppies and goldfish. and I’ve formed a pretty clear opinion on them. Guppies are my preference because they breed fast enough that you can maintain your own colony, which cuts out most of the disease risk. That said, my honest recommendation is to treat feeders as a bridge: useful while you’re transitioning a fish onto prepared foods, but not something I’d rely on long-term. Here’s what you need to know before using them.
Key Takeaways
- Predatory fish can be fed an assortment of feeder fish.
- Feeder fish can vary in size and quality, so it’s important to buy the right ones for your fish.
- The best feeder fish are raised in their own aquarium with a high-quality diet.
- A nutritious feeder fish can be fed once or twice a week depending on the species and the size of the predator.
What Are Feeder Fish?

Feeder fish are any type of fish that has been bred to serve as food for other aquatic life. This can include an array of species, both freshwater and saltwater.

Feeder fish are often seen in local fish and pet store locations. They are usually kept by the dozens or hundreds in a big, empty tank. These are usually feeder goldfish, guppies, platies, or other tropical livebearers, and are priced at less than $1.00 each.

Unfortunately, these fish are not kept in the best conditions. They are seen as highly disposable and not worth the cost of upkeep. As a result, infection, disease, and mutations run rampant. This makes it very easy for these same ailments to be added to the home aquarium during feeding times. For this reason, many hobbyists who heavily rely on feeder fish breed their own stock.

Feeder fish can also be well-fed guppies and platies from a heavily planted display aquarium. Many hobbyists understand that the love and care they give for feeder fish translates into the overall health of their predatory fish. For this reason, many hobbyists with carnivorous fish raise their own feeder fish in regular aquarium conditions. Some even plump their feeder stock up with high-quality foods to ensure that their bigger fish get a nutritious treat.

Benefits To Live Food

For years, there has been discussion surrounding the ethics of feeding live fish to aquarium fish. With all the great food options available, some hobbyists don’t see it necessary to offer live food. While we can’t tell you what’s right or wrong, we can give you some of the benefits of feeding live fish.

Enrichment

The biggest benefit of offering live fish as food is providing enrichment for other fish. Fish are limited to their tank environment, and they likely get bored every now and then. They might even get tired of having the same thing for dinner every night in a row.

Offering feeder fish provides a new enrichment element in the tank by making the other fish use their predatory instincts. This can stimulate your fish’s instincts and activity levels.

Natural Habitat

A predatory species likely eats other fish in the wild. This isn’t always true as some fish are strictly insectivores, but if your fish can fit another species in its mouth, then it’s likely that they eat fish in their natural habitat.

Nutrients

While aquarium foods are usually packed with nutrients, one food can’t cover every single mineral and nutrient. Because of this, most hobbyists have a rotating diet with many different food options. One of these options might be feeder fish.

If the hobbyist chooses to raise their own feeder fish, then there is even greater control over nutrient intake for both the prey and the predator.

Sometimes It’s Necessary

One reason live food might be necessary is that your fish might be wild caught. While many fish have been successfully bred in the aquarium hobby, some are still collected. Unless they are shown how to eat flake or pellet food, they might need to be given a strictly live diet for a while. This is also true if the fish is picky.

Types

The most common types of feeder fish to see for sale are goldfish and guppies. Depending on whether you have access to a bait shop or a more specialized store, you might have access to better, and sometimes cheaper, alternatives.

Here are some of the different options you might come across and how each can be fed!

Bluegill

Bluegills are very common North American freshwater fish found in ponds and lakes. They are scientifically known as Lepomis macrochirus and are often sold for freshwater fishing.

While some hobbyists catch bluegills to keep as aquarium pets (check with state laws as this could be illegal), others use these fish as food for their other pond fish, like bass. These fish may be found for sale in a commercial fishing store, but are most often caught from local waterways. This can introduce parasites and other diseases into the aquarium.

Another consideration to take into account is that bluegills are large fish that grow up to a foot long. While they are often sold as juveniles under 5 inches, if your fish doesn’t eat, then you might end up with a bluegill tank mate! Bluegills are also relatively aggressive, which could become problematic in the future.

Goldfish

Goldfish, Carassius auratus, are arguably the most common feeder fish available as both freshwater and saltwater predators eat them. They are easy to find and usually marked at an extremely low price. However, there are a lot of problems that can come with goldfish.

As you may know, goldfish are some of the messiest fish in the aquarium hobby. Setting up and maintaining a healthy supply of goldfish can be difficult for the average aquarist. Purchasing live goldfish from the store can also be challenging as disease runs rampant in unclean and unmonitored store tanks.

The same problem arises from keeping goldfish as bluegills, and that’s that goldfish can grow to extreme sizes depending on the breed. While some breeds stay small, under 4 inches, others can grow to be a couple feet. Unless you know how to identify breeds of goldfish (and not trust what they’re listed as at the store) then you might not know what you’re getting yourself into.

There is another underlying problem that hobbyists aren’t even aware of: thiaminase. Thiaminase is a necessary enzyme that helps break down vitamin B1 in several species, including goldfish. Though this enzyme is essential for the fish, ingesting large amounts of it can lead to thiamin deficiency in other organisms.

Guppies

Guppies are another popular choice and the term includes some subcategories. These fish often cost even less than goldfish and are just as available. As these fish stay under about 1.5 inches, they can be fed to a variety of tropical fish.

🏆 My pick among feeder fish: Guppies are my preference over feeder goldfish. They’re smaller, they breed incredibly fast, and if you raise your own colony in a spare 10-gallon tank at home, you sidestep the biggest disease risk altogether. A healthy home colony can easily keep pace with most predatory fish.

Commercial feeders suffer from the same poor conditions as goldfish, meaning that disease and infection can easily be transmitted. Many species of guppy also contain thiaminase, which can start to affect the animals being fed after prolonged ingestion.

Other alternatives to guppies might be:
- Mosquito Fish (2.8 inches)
- Minnows (2.5 inches)
Mosquito fish, minnows, and guppies are often sold alongside each other as feeder fish. You may not even be able to tell them apart when they’re kept in the same poor conditions. Luckily, they are very easy to breed in the home aquarium and can be fed with high-nutrition foods.

Unfortunately, both of these fish still increase the chances of thiamin deficiency.

Platies

Platies are less commonly found as feeder fish, but many aquarists use them in their own homes as they reproduce rapidly. These fish also stay between 2-3 inches, which makes them easy to feed to most moderately-sized fish.

If you’re going to feed feeder fish, then platies are probably some of the most reliable, as long as you’re breeding your own. These are easy and hardy fish that can easily be fed and prepared for feeding. As of now, platies are also not known to cause thiamin deficiency in other animals¹.

Why Are They Bad?

While there are definitely benefits to giving feeder fish to predatory species, like enrichment and nutritional value, there are a lot of reasons why you might be hesitant to try. Here are some remarks from esteemed aquarist and scientist Dr. Neale Monks (see his full article at WebWebMedia).

Disease and Illness

As already mentioned, most feeder fish from pet stores are diseased. These are cheap fish that are disposable and will not have their tanks properly taken care of. This, in addition to a high turnover rate, makes it a near-guarantee that some ailment or bacteria will unknowingly enter your aquarium during feeding times.

⚠️ From my experience: Disease management is the #1 issue I warn people about with feeder fish. Store-bought feeders are kept in severely overcrowded tanks with minimal care. the conditions are rough. I’ve seen ich and bacterial infections introduced this way more than once. If you’re committed to using live feeders, breeding your own guppy colony at home is far safer than buying off the shelf.

Poor Nutritional Value

Yes, feeder fish provide different nutrients than your fish would normally get from a singular fish food. However, a feeder fish is only as nutritional as the nutrition it eats. Since feeder fish aren’t usually taken care of in a commercial setting, they provide little to no additional nutritional benefit.

Thiaminase

The enzyme thiaminase can also cause more trouble than what it’s worth. This is an enzyme that’s necessary for breaking down vitamin B1 in many species, including goldfish, minnows, and other invertebrates. Overindulgence of a thiaminase source, like feeder fish, can start to cause a thiamin deficiency in the predator. This can quickly lead to health problems that may not be obvious to treat and eventual death.

How To Keep Them Healthy

The key to a happy and healthy fish is giving happy and healthy feeder fish. This means only purchasing from fish stores that keep clean and healthy tanks, and setting up your own breeding tanks if possible.

This setup doesn’t need to be extensive, but it should support whichever species you choose to raise. There are a few things to keep in mind when choosing a feeder:
1. Pick a species that can be easily eaten. In terms of size, your fish should be able to swallow the other fish without any problems. Avoid species with sharp fins or body features that could potentially damage your fish’s mouth or esophagus.
2. Pick a livebearer species. Livebearer species are practically self-sustainable and will provide food for your fish as long as you give them a space to do so. It is also recommended to keep herbivorous livebearers as they can be given plenty of nutritional value through algae flakes and pellets..
3. Price. Of course, you will need to consider the price if planning to feed store-bought fish. Keep in mind that you don’t need to feed your fish fresh food every day of the week. In fact, it’s better to only feed them once or twice a week! Still, you will need to consider the price, frequency, availability, and quality of the feeders.
Can you feed your fish other fish?

Yes! Many species of tropical fish available are predatory fish that rely on consuming other fish and animals for nutrition. In their natural habitat, they would receive nutrients and enrichment from hunting, which can be replicated in the aquarium setting.

What is the best feeder fish?

The best feeder fish is one that has been prepared for feeding. Many pet stores have feeders available, but their tank setups usually suffer from overpopulation and poor water quality. The best feeder will come from a clean setup that receives plenty of nutritional value.

How often should you feed live fish?

Live fish should be given as a treat once or twice a week. Depending on the size of the fish, and the size of the feeders, your fish might only need to hunt every couple of days.

If your feeder fish are from a reputable source, you may be able to keep uneaten food in the tank. Otherwise, they should be removed.

Conclusion

One of the reasons you likely got a predatory fish is to feed it! Feeding time can be exciting, and offering live foods can be a great way to introduce enrichment and additional nutrients into the aquarium. However, there are a few considerations that need to go into picking the right feeder fish, like size and quality. For the best results, raise live fish in a secondary aquarium.

🐟 Want to learn more? This article is part of our complete Aquarium Care Guide. your ultimate resource for water chemistry, maintenance, feeding, disease prevention, and everything you need for a healthy tank.
March 13, 2024
The 21 Smallest Aquarium Fish in the Trade: My Picks After 25 Years
I’ve personally kept several fish from this list. chili rasboras, pea puffers, and zebra danios. and cared for virtually all of them during my years working at local fish stores. The single most important thing I tell people getting into nano fish: don’t let the small size fool you into thinking a small tank will do. Every fish on this list needs to be kept in a group, and a group still needs space. I always push people toward a 10-gallon minimum, with bigger being better. Here’s my full breakdown of the 21 smallest aquarium fish in the trade.
Key Takeaways
- One of the smallest fish in the aquarium trade is the dwarf pygmy goby.
- The world’s smallest fish is believed to be Paedocypris progenetica, an unnamed fish from Sumatra.
- Small aquarium fish don’t require any additional consideration, but tank mates should have a similar temperament.
- Popular small fish include zebra danios, chili rasboras, dwarf pea puffers, and white cloud minnows.
The 21 Smallest Aquarium Fish In The Trade

Some of the smallest fish in the world can be brought into the home aquarium. What they lack in size they bring in color, movement, and excitement. Check out the video from our YouTube Channel.

It should be noted that just because these fish are small does not necessarily make them the most affordable or hardy species. Some may also be limited in availability or difficult to find.

1. Dwarf Pygmy Goby

View this post on Instagram

A post shared by Yapak PH (@yapak_ph)
- Scientific Name: Pandaka pygmaea
- Adult Size: 0.35-.0.45 inches
- Tank Size: 5 gallons
- Temperament: Peaceful, bottom-dwelling
To begin this list, we start with one of, if not, the world’s smallest fish species: the dwarf pygmy goby. Also known as the Philippine goby, these incredibly tiny fish max out at just under a half-inch long. They have mottled black, brown, and white colors with a typical elongated goby body.

The dwarf pygmy goby originates from muddy bottoms throughout Southeast Asia. They regularly move between freshwater and brackish conditions; many hobbyists prefer keeping them in medium salinity, but they can also be kept in purely fresh conditions.

Unfortunately, the dwarf pygmy goby is a critically endangered species and distribution is highly limited. Hobbyists are most likely to find these fish available for purchase near their natural habitats.

2. Exclamation Point Rasbora

Exclamation Point Rasbora” class=”wp-image-1063164″/>
- Scientific Name: Boraras urophthalmoides
- Adult Size: 0.50-0.65
- Tank Size: 10 gallons
- Temperament: Peaceful, shy
The exclamation point rasbora is colorful and aptly named for the black-and-orange-outlined ‘!’ on the sides of its body. These fish are native to Thailand but can be found for sale throughout the aquarium industry relatively easily.

The exclamation point rasbora needs to be kept in larger groups, with most hobbyists recommending a school of at least 10 or more. This is because these fish are very shy and skittish and will find comfort in a larger school. For the same reasons, the aquarium should be densely planted with plenty of floating plants. Tank mate compatibility is also limited.

3. Chili Rasbora

Chili Rasboras

Use Promo Code ASDFLIPPROMO
A great nano schooling fish. Males display brighter colors. Best in groups of 6 or more

Click For Best Price
- Scientific Name: Boraras brigittae
- Adult Size: 0.75-1.0 inches
- Tank Size: 10 gallons
- Temperament: Peaceful
The chili rasbora has gained popularity over the past few years as being one of the best freshwater species that only grow to an inch. These fish are firey-orange and will bring tons of color and movement to the aquarium.

Like most other small fish, chili rasboras are shy schooling fish that excel in a large group with plenty of vegetation. If keeping no other fish, a 10 gallon aquarium can comfortably keep a school of 20 individuals.

🏆 My top pick from this entire list: Chili rasboras are my #1 recommendation for nano tanks. I’ve kept them personally and they’re absolutely stunning in a large group against a planted background. The color payoff in a well-planted 10-gallon is hard to beat. they look like living embers.

The chili rasbora is a relatively hardy fish that can adapt to some changes in water parameters, but good tank husbandry is a must. With excellent care, these fish can live to be 8 years old!

4. Fire Ember Tetra

View this post on Instagram

A post shared by CALA Nature Scapes (@cala_scapes)
- Scientific Name: Hyphessobrycon amandae
- Adult Size: 0.75-1.0 inches
- Tank Size: 10 gallons
- Temperament: Peaceful
Similar in appearance to the chili rasbora, the fire ember is bright orange. However, fire embers are hardier, less skittish, and much more affordable than chili rasboras.

Fire ember tetras originate from the Amazon River in South America. They prefer a heavily planted aquarium and a school of at least 6 or more. These small fish have been captive-bred and can be kept in a wide range of aquarium conditions.

5. Least Killifish

View this post on Instagram

A post shared by Steve Christman (@fishliquor5)
- Scientific Name: Heterandria formosa
- Adult Size: 0.75-1.50 inches
- Tank Size: 10 gallons
- Temperament: Peaceful
Though they’re named killifish, least killifish are not true killifish and are a type of minnow instead. This means that they are small, hardy fish that can complete a natural biotope setup or densely planted aquarium. They are also one of the few aquarium species available that is native to the southeast United States.

Least killifish are one of the smallest species of minnow available, making them a perfect addition to the nano aquarium. These are not schooling fish, but they greatly enjoy the company of others.

6. Pygmy Sunfish

View this post on Instagram

A post shared by べりる (@veriru_kingyo)
- Scientific Name: Elassoma spp.
- Adult Size: 1.0-1.5 inches
- Tank Size: 10 gallons
- Temperament: Shy, live-feeders
Pygmy sunfish are sure to make a big splash in the aquarium hobby in the near future. These electric black and blue fish almost resemble a small species of cichlid, without the aggression. Instead, these fish are native to the southeast United States and display paired mating behaviors.

Pygmy sunfish are currently difficult to find for sale, though demand is growing. There is one major challenge that comes with keeping these fish though, and this is that they require a live food diet. They are ambush predators and need to hunt for prey that wiggles and moves.

The best home for a pygmy sunfish will have a live food system up and running.

7. Pygmy Corydoras

Pygmy Cory

A smaller variety of Cory Catfish. Grows to less than 1.5 inches in length. A peaceful bottom dwelling fish

Click For Best Price
- Scientific Name: Corydoras pygmaeus
- Adult Size: 0.75-1.5 inches
- Tank Size: 10 gallons
- Temperament: Peaceful, bottom-dwellers
Though some of the other tiny fish on this list might be hard to find at your local fish store, the pygmy corydoras is luckily easy to find.

These small bottom-dwellers are native to Brazil and appreciate a soft substrate with plenty of live plants. They have natural brown and white colors and are easy to tell apart as females are almost double the size of males! They are very difficult to breed in the home aquarium but have been done so successfully at a commercial scale.

Pygmy corydoras are one of the few species on this list that can be safely housed with larger tropical fish. As long as they are kept in schools of at least 6 or more and are given plenty of coverage, they will do well in a traditional community tank setup.

8. Dwarf Pea Puffer

Freshwater Pea Puffers

At only an inch in length, this is the smallest pufferfish you can purchase in the aquarium hobby

Click For Best Price
- Scientific Name: Carinotetraodon travancoricus
- Adult Size: 1 inch
- Tank Size: 10 gallons
- Temperament: Semi-aggressive
Maybe not the smallest fish on this list, the dwarf pea puffer is certainly the most adorable. These plump little fish are one of the only true freshwater species of puffer; most other species prefer brackish waters. Instead, these fish do best in a heavily planted freshwater aquarium.

🐡 From my experience: Pea puffers have enormous personalities for such a tiny fish. I’ve kept them and always enjoyed them, but they can be nippy with tank mates. They do best in a species-only setup or with very carefully chosen companions. Rewarding fish, just go in with the right expectations.

The dwarf pea puffer might be small, but they can be aggressive. The problem is that males and females look the same to us, but males can tell each other apart. Male pea puffers can be territorial towards other males in the tank, especially during breeding periods. Because of this, it might take some time to work out a compatible male-to-female ratio.

9. Clown Killifish

Clown Killifish

A colorful nano killifish. Best in low flow tanks

Click For Best Price
- Scientific Name: Epiplatys annulatus
- Adult Size: 1.0-1.5 inches
- Tank Size: 5 gallons
- Temperament: Peaceful, predatory
Also known as the banded panchax, the clown killifish is a very interesting fish to keep. These might not be the smallest fish on the list, but they’re one of the smallest and most effective predators. The clown killifish stays just below the surface of the water, waiting for insects and other small organisms to land. When ready, they use their upturned mouths to quickly catch their prey!

In the aquarium setting, this can be replicated by offering small insects, such as fruit flies and mosquito larvae. While predators, clown killifish can be kept alongside a variety of community tank species, like tetras and corydoras. However, they are rather solitary and enjoy the company of one or two others.

10. Spotted Blue Eye Rainbowfish

View this post on Instagram

A post shared by Schmerle36 (@meine_fischis_ziehen_um)
- Scientific Name: Pseudomugil gertrudae
- Adult Size: 1 inch
- Tank Size: 10 gallons
- Temperament: Peaceful, shy
Possibly the most beautiful fish on this list, the spotted blue eye rainbowfish is a shimmering bluish-yellow with elongated speckled fins. Because of their appearance, these are also some of the most expensive fish listed.

The spotted blue eye rainbowfish only grows to be about an inch at mature size. They originate from shallow, slow-moving waterways throughout Southeast Asia as well as Australia. Spotted blue eye rainbows can withstand low pH levels, making them a good candidate for blackwater or biotope setups.

These fish do best in groups of at least 6 or more and as one of the only species in the aquarium. They are often kept with peaceful bottom-dwellers, including snails and shrimp.

11. Green Neon Tetra

Green Neon Tetra School” class=”wp-image-1067276″/>
- Scientific Name: Paracheirodon simulans
- Adult Size: 0.75-1.0 inches
- Tank Size: 10 gallons
- Temperament: Peaceful
The green neon tetra isn’t seen in the aquarium as often as the more recognizable neon tetra, but these tiny fish do well in a school in most tank setups. A few considerations are needed to keep them, though.

While tetras are seen as some of the hardiest fish in the aquarium hobby, green neon tetras are a little more sensitive to imperfect water conditions. These fish originate from exclusively blackwater conditions in South America. This means that blackwater conditions with soft, acidic water parameters need to be matched in the home aquarium. They also need heavy plant coverage, preferably with leaf litter that sustains a natural population of small foods.

12. Kubotai Rasbora

View this post on Instagram

A post shared by Karine 🪷 (@karine_aquarium)
- Scientific Name: Microdevario kubotai
- Adult Size: 0.50-1.0 inches
- Tank Size: 10 gallons
- Temperament: Peaceful
One of the less common species of rasbora, the Kubotai rasbora is hard to miss! These fish are naturally neon green from Southeast Asia.

For their size, these rasboras originate from moderately-flowering waterways. This, in addition to plant life, makes the water highly oxygenated, which should be recreated in the aquarium setting with plants and air bubblers. Surface water may also be agitated as long as it’s not overpowering the rasboras.

Otherwise, Kubotai rasboras are relatively straightforward to keep as long as water parameters are maintained. They are a schooling fish that need to be kept in a group of at least 6 or more. Tank mate pairing may be difficult as other inhabitants must also be a similar size and be able to withstand a moderate water flow.

13. White Cloud Minnow
- Scientific Name: Tanichthys albonubes
- Adult Size: 1.5 inches
- Tank Size: 10 gallons
- Temperament: Peaceful, active
While many of the smallest aquarium fish are fun and cute to look at, many are shy and reclusive. If you’re looking for something small and active, the white cloud minnow might fit your next coldwater aquarium setup!

The white cloud minnow is a bold fish with a silver body, bright white horizontal stripe, and unmistakable red fins. They originate from China but have been found in other regions of Southeast Asia. Unfortunately, they are nearly considered extinct in their natural habitat.

Luckily, these are some of the easiest fish to keep in the aquarium hobby and are highly prolific! They will naturally mate when kept in a school of 6 or more. White cloud minnows are a coldwater species, which means that tank mate pairing can be tricky. They also require some water flow and are relatively active in the top and middle portions of the aquarium.

14. Glowlight Tetra

Glowlight Tetra” class=”wp-image-1084544″/>
- Scientific Name: Hemigrammus erythrozonus
- Adult Size: 1.5-2.0 inches
- Tank Size: 10 gallons
- Temperament: Peaceful
You might think that glowlight tetras are artificially dyed, but these bright orange fish are all natural! These tetras are a little bigger than the other species on this list, but they’re a perfect addition to a more active community tank.

Glowlight tetras originate from South America and do best in a heavily planted aquarium with a dark substrate that lets their natural colors show. These fish are a loose schooling species and need to be kept in groups of at least 6 or more. If they’re swimmingly together in a tight school, then they might be overwhelmed by the other tank mates in the aquarium and a larger school may be necessary.

15. Dwarf Emerald Rasbora

Dwarf Emerald Rasbora

A colorful Rasbora fish that needs large numbers for its personality to really show. Needs at least a group of 10.

Click For Best Price
- Scientific Name: Danio erythromicron
- Adult Size: 1.0-1.5 inches
- Tank Size: 10 gallons
- Temperament: Peaceful
The dwarf emerald rasbora is not a common species to see at your local fish store, but these fish complement the colors and behaviors of celestial pearl danios and other small tetras. They may also be advertised as a thick band purple zebra danio.

Dwarf emerald rasboras have a very limited range in Inle Lake, Myanmar. They are shoaling fish and the male-to-female ratio needs to be balanced. Males are slightly smaller but more colorful than their female counterparts. Because they’re so small, these fish do best in groups of at least 10 or more.

Another concern surrounding the dwarf emerald rasbora is during feeding time. Though these fish are confident in numbers, they can be outcompeted during feeding times by other more active species. They also have small mouths, which means that they might have difficulty eating some foods.

16. Borneo Sucker Loach

View this post on Instagram

A post shared by Pea Puffer (Carinotetraodon travancoricus) (@pea_puffer_fry)
- Scientific Name: Gastromyzon punctulatus
- Adult Size: 1.5-2.0 inches
- Tank Size: 20 gallons
- Temperament: Active, social
Another species not commonly found for sale in the hobby is the Borneo sucker loach, also known as the spotted borneo sucker. These fish are named after the country they originate from and the small yellow spots that cover their dark body.

The Borneo sucker loach is a relatively challenging fish to keep. These loaches need high water flow, and social groups of at least 4 or more. They should have a healthy supply of natural algae available, but will also need high-quality algae wafers and flakes.

Other tank mates should be able to tolerate a more active and outgoing species. Though these loaches aren’t aggressive, other small and timid fish might be overwhelmed.

17. Zebra Danio
- Scientific Name: Danio rerio
- Adult Size: 1.0-2.0 inches
- Tank Size: 10 gallons
- Temperament: Active
The zebra danio is a staple fish in the aquarium hobby. While they’re not the world’s smallest fish, they’re one of the most recognizable.

The zebra danio originates from parts of Southeast Asia and especially prefers cold water temperatures. However, they have been successfully bred and adapted to the aquarium hobby for years and can now be kept in nearly every temperature range.

These fish are extremely hardy and can be paired with most fish that fit inside their preferred temperature zone. Zebra danios prefer the upper portions of the water column, where they’ll zoom back and forth across the tank in their school. Smaller, less active tank mates should be avoided.

🐟 From my experience: Zebra danios were one of the first fish I kept and they remain one of the best starter fish in the hobby. They’re incredibly hardy, active schoolers, and nearly bulletproof. a great choice if you’re new to nano tanks and want something forgiving.

19. Gardneri Panchax Killifish

View this post on Instagram

A post shared by Michael Hille (@zierfischzuchthille)
- Scientific Name: Fundulopanchax gardneri
- Adult Size: 2.0-2.5 inches
- Tank Size: 20 gallons
- Temperament: Peaceful
One of the most colorful fish on this list, the Gardneri Panchax killifish grows well over one inch but can fill a small aquarium all on their own. Males are brighter in color, but both males and females feature bright green, orange, red, and blue coloration. These fish originate from unique marsh habitats that experience seasonal droughts throughout areas of Africa, like Nigeria and Cameroon.

Because of their changing environment, these killifish are very hardy and do well in most aquarium setups. A tight aquarium hood is necessary.

20. Scarlet Badis

Scarlet Badis

A great colorful nano fish. They are known for being semi-aggressive. Best if keep solo or in pairs

Click For Best Price
- Scientific Name: Dario dario
- Adult Size: 1 inch
- Tank Size: 10 gallons
- Temperament: Generally peaceful
The scarlet badis is a perfect freshwater nano fish for hobbyists who prefer cichlid behavior. Badis are like mini-cichlids, just without the aggression!

The scarlet badis is a colorful red and blue fish that originates from India and Bhutan. When ready, males and females form mating pairs. Males can become aggressive towards each other during these times, so it’s recommended to only keep one male and female per tank.

Otherwise, scarlet badis are timid fish that will shy away from more active and overbearing species. They need plenty of plants and hiding spots to spawn and to feel safe. These fish also need a high-quality diet mixed with flake food and live food, but should not be overfed as they’re prone to obesity.

21. Emerald Eye Rasbora

View this post on Instagram

A post shared by Aquaristik Kosmos (@aquaristik_kosmos)
- Scientific Name: Rasbora dorsiocellata
- Adult Size: 1.0 inch
- Tank Size: 10 gallons
- Temperament: Peaceful
Another less commonly known rasbora, the emerald eye rasbora is simple in color with a greenish-grey body and highlighted dorsal fin. These fish originate mainly from Thailand but can be found throughout flowing streams across Southeast Asia.

Emerald eye rasboras have peaceful schooling behaviors. They do well as a background fish in a school of 6 or more but may be timid around more active species.

Other Species

There are two species listed below that are not available for aquariums and the others are often mentioned, but we ran out of space. Let me know in the comments if we missed any fish and I’ll add them to the list.
- Midget dwarf goby
- Corfu dwarf goby
- Celestial pearl danio (AKA Galaxy Rasboras)
- Mosquito rasboras
- Bettas (AKA Siamese Fighting Fish) – They can live in small tanks but aren’t small themselves)
- Harlequin Rasbora – popular, but too big to be considered for this list
Conclusion

Wanting to keep the smallest fish in the world in the smallest aquarium possible? Many species of fish stay under an inch long, and even more stay under 2 inches long. Most species of small fish don’t require any special considerations in terms of aquarium requirements, but some may be more easily intimidated by larger and more active species than others.

It’s also important to keep in mind that many small fish are jumpers, so a tight aquarium lid is necessary!

📘 Want to learn more? This article is part of our complete Freshwater Fish Guide. your ultimate resource for freshwater species, care tips, tank setup, and more.
March 12, 2024
Fish for a 55 Gallon Tank: My 21 Picks After Years in the Aquarium Trade
I’ve personally cared for nearly every fish on this list through my years working at local fish stores, so I can tell you firsthand which ones thrive in a 55-gallon setup and which ones cause problems. A 55-gallon tank is a fantastic size. it opens the door to impressive centerpiece fish and schooling communities alike, but that wide range of options is exactly where most fishkeepers go wrong. In this guide, I’ll share my top 21 picks, along with the stocking mistakes I see most often so you can avoid them.
Key Takeaways
- There are hundreds of different fish species that you can keep in a 55-gallon tank
- This tank size is a great choice for large, single-fish setups like oscar aquariums or a busy community aquarium filled with plants and colorful nano fish.
- Tank size is not the only factor when choosing fish. Take note of each species’s water parameter requirements and select fish that will thrive in your local water.
Best Freshwater Fish For 55 Gallon Tanks

Let’s start our list right away. You can check out this video from our official YouTube Channel while following along on this blog post. If you like our content be sure to subscribe!

1. Freshwater Angelfish

Altum Angelfish” class=”wp-image-551860″/>
- Scientific name: Pterophyllum scalare
- Care level: Easy
- Minimum tank size: 40 gallons
- Temperament: Generally peaceful but may be aggressive when breeding and will eat nano fish
- Adult fish size: 6 inches
- Origin: South America
- Temperature: 75 – 82°F
- pH: 6-7
- Diet: Omnivore
- Swim Level: Mid-level
- Type: Centerpiece
Freshwater angelfish are some of the most beautiful and elegant fish in the hobby and they can thrive in a standard four-foot aquarium. These stunning South American Cichlids are available in a range of different breeds, ranging from pure white to black, and even multicolored.

A pair of angelfish in a 55 gallon planted tank is usually a great idea, just be aware that these fish can show some territorial behavior around breeding time, and they will snack on nano fish when they can catch them.

🏆 My top pick for a 55-gallon centerpiece: If I were setting up a 55-gallon freshwater community tank, angelfish would be my first choice. A pair in a well-planted setup is genuinely stunning. I’ve seen this work beautifully countless times through my years in the aquarium trade. Just plan your community around them from the start, and avoid adding nano fish as tank mates.

2. Congo Tetra
- Scientific name: Phenacogrammus interruptus
- Care level: Easy
- Minimum tank size: 30 gallons
- Temperament: Peaceful
- Adult fish size: 2.5-3 inches
- Origin: West Africa
- Temperature: 73-82°F
- pH: 6-7.5
- Diet: Omnivore
- Swim Level: Middle and upper levels
- Type: Schooling fish
The Congo tetra is a beautiful African schooling fish that is ideal for larger aquariums. Males are neon blue with an orange horizontal stripe and interesting pointed tail fins. Females have a classy gold/silvery color with shorter tails and more compact dorsal fins.

A school of six or more fish will add variety and heaps of movement to the water column of your 55-gallon tank.

3. African Cichlids
- Scientific name: Various
- Care level: Moderate
- Minimum tank size: Various
- Temperament: Semi-aggressive
- Adult fish size: 1.5 – 5 inches
- Origin: East Africa
- Temperature: 77-82°F
- pH: 7.5-9
- Diet: Species dependant
- Swim Level: Lower and middle levels
- Type: Centerpiece fish
A four-foot tank is just large enough for an African cichlid setup, although it’s important to choose the right species to minimize territorial disputes and provide the hard, high-pH water these fish require.

Smaller mbuna cichlids like yellow labs or other smaller species like shell dwellers are ideal for this tank size, although you could also start a breeding group of a slightly larger species like one of the smaller peacocks.

4. Synodontis Catfish
- Scientific name: Synodontis spp.
- Care level: Easy-moderate
- Minimum tank size: 30-50 gallons
- Temperament: Peaceful/ Semi-aggressive
- Adult fish size: 4-8 inches
- Origin: East Africa
- Temperature: 74-82°F
- pH: 7.5 – 8.5
- Diet: Omnivore
- Swim Level: Bottom
- Type: Bottom dweller
There are several species of Synodontis catfish available in the aquarium hobby, and these interesting fish are especially popular as bottom-dwelling tankmates in an African cichlid tank.

Of course, you could keep these bottom-dwelling fish with other suitable tank mates, but avoid small, slow-moving species that might turn into lunch. Synodontis catfish prefer the company of their own kind, so pick up a school of four or more.

5. Discus
- Scientific name: Symphysodon discus
- Care level: Advanced
- Minimum tank size: 55 gallons (75+ is better)
- Temperament: Peaceful
- Adult fish size: 5-6 inches
- Origin: South America
- Temperature: 82-89°F
- pH: 6-6.5
- Diet: Omnivore
- Swim Level: Middle levels
- Type: Centerpiece
It is possible to keep discus cichlids in a tank as small as 55 gallons, but I must emphasize that you’re going to need to stay dedicated to maintain their water quality!

So, if you’ve always dreamed of keeping the ‘king of the aquarium’ but you don’t have space for a bigger tank, you could attempt this species. Be prepared to perform frequent water changes to keep these delicate fish happy and healthy.

6. Corydoras Catfish

Habrosus Cory Catfish

A small and active cory catfish. Does best in groups of at least 5

Click For Best Price
- Scientific name: Corydoras spp.
- Care level: Easy
- Minimum tank size: 30 gallons for most species
- Temperament: Peaceful
- Adult fish size: 2-3 inches
- Origin: South America
- Temperature: 74-80°F
- pH: 5.5-8
- Diet: Omnivore
- Swim Level: Bottom
- Type: Bottom dweller
Corydoras catfish can be kept in tanks as small as 30 gallons, although a four-foot tank will allow you to keep a larger school or even a few different species. These peaceful fish hang out on the bottom of the tank and they love to search the substrate for leftover food scraps.

There are many different types, including panda cories, Sterbai cories, and even albino breeds, but these social fish really need the company of their own kind. Pick up a school of at least 5 of the same species and provide a sinking bottom feeder tablet to keep them in good health.

7. Ram Cichlids
- Scientific name: Mikrogeophagus ramirezi
- Care level: Moderate – Advanced
- Minimum tank size: 20 gallons
- Temperament: Peaceful
- Adult fish size: 2.5 inches
- Origin: South America
- Temperature: 78-86°F
- pH: 5.5-7.5
- Diet: Omnivore
- Swim Level: Lower levels
- Type: Centerpiece
The ram is a colorful dwarf cichlid from South America. These gorgeous fish are relatively shy and sensitive for a cichlid, but they can make a great addition to a 55-gallon aquarium.

Ram cichlids hang out at the bottom of the tank and sift through the substrate in search of a meal, so a sand substrate is ideal. These tropical fish require warm water, so set your heater in the low 80s to recreate their natural habitat.

8. Neon Tetras

Neon Tetra

Use Promo Code ASDFLIPPROMO
One of the most popular freshwater community schooling fish available in the aquarium trade. Great neon blue colors!

Click For Best Price Buy From Petco Online
- Scientific name: Paracheirodon innesi
- Care level: Moderate
- Minimum tank size: 10 gallons
- Temperament: Peaceful
- Adult fish size: 1.5 inches
- Origin: South America
- Temperature: 70-79°F
- pH: 6-7
- Diet: Omnivore
- Swim Level: Middle levels
- Type: Schooling fish
Who says you can’t keep small fish in a big tank? The neon tetra is a classic community fish that will thrive in a large aquarium filled with live plants and other small peaceful species. These fish look their best in a large school, so a 55-gallon is ideal for the species.

9. Small to Mid-sized Plecos
- Scientific name: Ancistrus spp., Hypancistrus spp. Panaqolas spp. etc.
- Care level: Easy-Advanced
- Minimum tank size: 20 gallons
- Temperament: Peaceful
- Adult fish size: 3-6 inches
- Origin: South America
- Temperature: Species dependant. Some prefer low 70s Fahrenheit while others prefer mid-80s
- pH: Slightly acidic-slightly basic (Most species will do well in neutral conditions)
- Diet: Herbivore
- Swim Level: Bottom
- Type: Bottom dweller
There are well over a hundred pleco species, some of which grow to more than a foot in length. However, there are many species in the hobby that are perfectly sized for a 55-gallon tank, and some will even help you keep algae under control.

These peaceful bottom dwellers are safe to keep with smaller fish, although they can also hold their own with medium-sized fish in community tanks. Include plenty of rocks and driftwood to create a natural environment with plenty of hiding spaces and food sources.

10. Geophagus
- Scientific name: Geophagus spp., Satanoperca spp., etc.
- Care level: Moderate
- Minimum tank size: 55 gallons for smaller species
- Temperament: Generally peaceful
- Adult fish size: 6+ inches
- Origin: South America
- Temperature: Species-dependant
- pH: Species-dependant
- Diet: Omnivorous
- Swim Level: Lower levels
- Type: Centerpiece
Geophagus are colorful South American cichlids characterized by their unique feeding style. These medium to large fish sift through the substrate in search of food, so they are not ideal fish for a carefully aquascaped tank!

Keep geophagus cichlids on a fine sandy substrate and choose smaller species that grow to about 6 inches or smaller (e.g., Geophagus tapajos).

11. Rainbowfish
- Scientific name: Melanotaenia spp.
- Care level: Easy-moderate
- Minimum tank size: 30 gallons
- Temperament: Peaceful
- Adult fish size: 2-6 inches
- Origin: Australia and Indonesia
- Temperature: 74-80°F
- pH: 6.5-8
- Diet: Omnivore
- Swim Level: Middle levels
- Type: Schooling fish
Rainbowfish are peaceful, schooling fish that will add color and movement to your 55-gallon aquarium. These fish have an interesting body shape, and there are many amazing species to choose from, including the popular Boesmani rainbow and the smaller dwarf neon rainbow.

Check out my guide to 15 popular rainbowfish types to find the perfect species for your tank!

12. Convict Cichlids
- Scientific name: Amatitlania nigrofasciata
- Care level: Easy
- Minimum tank size: 30 gallons
- Temperament: Aggressive
- Adult fish size: 3.5 – 6 inches
- Origin: South America
- Temperature: 74-84°F
- pH: 6.5-8
- Diet: Omnivore
- Swim Level: Lower levels
- Type: Centerpiece
Named for its grey color and vertical black stripes, the convict cichlid looks like it belongs in a prison! In fact, these South American cichlids are excellent fish for a 55-gallon aquarium, and they’re super easy to breed! In fact, these fish spawn so much that you may want to choose another species if you aren’t up for raising their tiny fry.

13. Tiger Barbs
- Scientific name: Puntigrus tetrazona
- Care level: Easy
- Minimum tank size: 30 gallons
- Temperament: Semi-aggressive
- Adult fish size: 3 inches
- Origin: Southeast Asia
- Temperature: 73-86°F
- pH: 6-8
- Diet: Omnivore
- Swim Level: Middle levels
- Type: Schooling fish
Named for its orange body color and four vertical black stripes, the tiger barb is an attractive schooling fish from Southeast Asia. These active barbs have a reputation for nipping other fish, although they tend to behave a lot better when kept in large schools of 15 or more.

Tiger barbs can be kept with many bottom-dwellers and fast-moving schooling fish, just avoid any slow-moving tankmates or fish with long, flowing fins. A Southeast Asian Biotope with tiger barbs, loaches, and a single red-tailed shark could make an interesting 55-gallon setup.

14. Rainbow Cichlid
- Scientific name: Herotilapia multispinosa
- Care level: Easy
- Minimum tank size: 20 gallons
- Temperament: Relatively peaceful
- Adult fish size: 4-5 inches
- Origin: Central America
- Temperature: 72-82°F
- pH: 7-8
- Diet: Omnivore
- Swim Level: Lower levels
- Type: Centerpiece
The rainbow cichlid is a beautiful Central American fish that is relatively peaceful as far as cichlids go. That being said, fish from the cichlid family are generally not recommended for the general community tank.

These fish have a beautiful golden color with a prominent black streak along each side that may be broken into blotches. A pair of rainbow cichlids would be an excellent choice for a planted 55-gallon tank with suitable tankmates.

15. Dension Barb
- Scientific name: Sahyadria denisonii
- Care level: Easy
- Minimum tank size: 55 gallons
- Temperament: Peaceful
- Adult fish size: 4 inches
- Origin: India
- Temperature: 59-77°F
- pH: 6.5-7.8
- Diet: Omnivore
- Swim Level: Middle levels
- Type: Schooling fish
Also known as the roseline shark, denison barbs are one of the best-looking barbs in the hobby. These speedy schooling fish combine sleek lines and silvery scales with a bright red streak and yellow tail spots.

Due to their size and active nature, a 55-gallon tank provides just enough swimming space for a small school (6+) of these peaceful freshwater fish. Denison barbs enjoy cooler water temperatures, so factor that in when selecting tank mates.

16. Electric Blue Acara
- Scientific name: Andinoacara pulcher
- Care level: Moderate
- Minimum tank size: 40 gallons
- Temperament: Semi-aggressive
- Adult fish size: 6-7 inches
- Origin: Trinidad and Venezuela
- Temperature: 74-82°F
- pH: 6-7
- Diet: Omnivore
- Swim Level: Lower half
- Type: Centerpiece
The electric blue acara is a particularly colorful breed of the regular blue acara and a favorite species in the aquarium hobby. These active South American cichlids add amazing color to a 55-gallon tank and their personality traits make them compatible with a wide variety of species, including other cichlids like angel fish and geophagus.

17. Giant Danio

Giant Danio in Aquarium” class=”wp-image-557080″/>
- Scientific name: Devario malabaricus
- Care level: Easy
- Minimum tank size: 40 gallons
- Temperament: Generally peaceful
- Adult fish size: 6 inches
- Origin: India and Sri Lanka
- Temperature: 65-77°F
- pH: 6-8
- Diet: Omnivore
- Swim Level: Middle and upper levels
- Type: Schooling fish
You probably know danios as tiny nano fish, but one species, the giant danio, doesn’t fit that category.

The giant danio is a beautiful fish, with gold to orange stripes on a cobalt blue body. These fast-swimming schoolers can reach over 6 inches, so a 55-gallon tank will provide just enough swimming space for a small group.

18. Fancy Goldfish
- Scientific name: Carassius auratus
- Care level: Moderate
- Minimum tank size: 20-30 gallons
- Temperament: Peaceful
- Adult fish size: 6-8 inches
- Origin: East Asia
- Temperature: 65-72°F
- pH: 7-8
- Diet: Omnivore
- Swim Level: All levels
- Type: Centerpiece
Goldfish are peaceful, long-lived pets with heaps of personality and various breeds to choose from. Fancy goldfish have been selectively bred into some surprising shapes and colors, including black moors, ranchus, and ryukins.

Many people associate goldfish with small glass bowls, although these fish actually need plenty of space. A 55-gallon tank is a great size for three or four adult fancy goldfish.

Check out my guide to 12 fancy goldfish types to find the perfect breeds for your tank!

19. Rosy Barbs

Rosy Barb” class=”wp-image-554575″/>
- Scientific name: Pethia conchonius
- Care level: Easy
- Minimum tank size: 30 gallons
- Temperament: Generally peaceful
- Adult fish size: 3-4 inches
- Origin: Southern Asia
- Temperature: 64-72°F
- pH: 6-8
- Diet: Omnivorous
- Swim Level: All levels
- Type: Schooling fish
Rosy barbs are peaceful schooling fish that prefer cool water aquariums. These fish have a golden-orange color, and males tend to be more colorful than females. Long-finned varieties are also available in the aquarium hobby.

A small school of these medium-sized fish will do well with many small to medium-sized community fish that enjoy the same conditions.

20. Female Bettas
- Scientific name: Betta splendens
- Care level: Moderate
- Minimum tank size: 5 gallons
- Temperament: Semi-aggressive/aggressive
- Adult fish size: 2.5 inches
- Origin: Thailand
- Temperature: 76-81°F
- pH: 6.5-8
- Diet: Carnivore
- Swim Level: All levels
- Type: Centerpiece
The most popular way to keep betta fish is to house a single male alone in a small aquarium. However, you may be surprised to learn that some aquarists successfully keep multiple female bettas together in the same tank.

This is known as a betta sorority tank, and it’s an interesting option for a 55-gallon aquarium. A sorority tank is not an ideal choice for a beginner, however, and the trick is to keep only females and a minimum group size of four to spread out aggression.

21. Mollies
- Scientific name: Poecilia spp.
- Care level: Moderate
- Minimum tank size: 20 gallons
- Temperament: Generally peaceful
- Adult fish size: 3-6 inches depending on the species
- Origin: North, Central, and South America
- Temperature: 72-82°F
- pH: 7-8.5
- Diet: Omnivorous
- Swim Level: Middle levels
- Type: Schooling fish
Mollies are medium-sized livebearers that are ideal for a 55-gallon aquarium. These interesting fish are highly adaptable and can even thrive in a saltwater tank, although they are usually kept in hard, freshwater aquariums.

There are three popular molly species, and they have been hybridized and bred into many beautiful colors and varieties, including the popular balloon molly and various other fancy breeds. Mollies get along with many other peaceful fish and can be kept in a community tank or a dedicated livebearer tank with guppies and other similar species.

⚠️ The biggest stocking mistake I see with 55-gallon tanks: Fishkeepers constantly underestimate how much aggression and size differences matter. Adding a small, peaceful species to a tank with a larger or semi-aggressive fish almost always ends badly. I’ve seen it play out dozens of times. Research the adult size and temperament of every fish before mixing species, and when in doubt, stick to fish with similar size and temperament profiles.

Other Options

All the fish mentioned in this guide are excellent options for a 55-gallon setup, although there are hundreds of other species that will thrive in this versatile tank size. I’ve narrowed this list down to just 21 options but you can get much more inspiration by exploring some of my other helpful guides.

Looking for more species? Check out the following posts!
- Schooling fish species- 15 to keep: A great guide for a variety of social community fish
- Fish breed types blog section – Explore a wide variety of articles on various fish breeds
- 21 Centerpiece fish for every tank size: A hand-picked selection of eye-catching display species
- 9 of the best bottom-feeder fish for your aquarium: Almost all of the species in this guide will thrive in a 55-gallon aquarium
- African cichlid species – 21 great choices: A high-level overview of some of the hobby’s most popular species
- Aggressive freshwater fish – 15 best: A collection of aggressive territorial fish that make exciting pets.
What fish can you put in a 55-gallon fish tank?

55-gallon tanks are big enough for most of the popular freshwater aquarium fish sold in fish stores, and there are hundreds of options. Of course, you will need to create a suitable habitat and provide appropriate water parameters for whichever fish you plan to keep.

What is the largest fish for a 55-gallon tank?

New World cichlids like Oscars and Jack Dempseys are about the largest fish you can keep in a 55-gallon, although they would prefer a larger tank when fully grown.

How do you stock a 55-gallon tank?

Start with your water parameters when stocking a new aquarium. If your water is naturally hard, you may have the ideal conditions for a livebearer tank or for smaller African Cichlids like yellow labs. Soft water is ideal for many tropical South American, Southeast Asian, or West African fish.

If you’re creating a community tank with several different fish species, make sure each fish will be comfortable in the water conditions you have and attempt to create the kind of habitat they prefer in nature.

Consider using a calculator like AqAdvisor for help on research.

How many fish can you have in a 55-gallon tank?

The total number of fish you can keep will depend on the size and requirements of the fish species. You could keep just a single large species like an adult Jack Dempsey cichlid, or choose a large school (dozens) of nano fish like chili rasboras or ember tetras if you want more fish.

What can I put in a 55-gallon tank besides fish?

Fish aren’t the only animals you can keep in a 55-gallon tank. You can also keep freshwater invertebrates like shrimp and snails, amphibians like axolotls and African dwarf frogs, or even small turtle species.

Final Thoughts

Choosing the right fish for an aquarium is an exciting but challenging task. Whether you’re considering a 55-gallon tank, or just researching the next fish to add to your existing setup, rest assured that all the fish discussed in this guide will work with the right care.

Do you have a 55-gallon aquarium? Tell us about your setup in the comments below!

📘 Want to learn more? This article is part of our complete Freshwater Fish Guide. your ultimate resource for freshwater species, care tips, tank setup, and more.

References
- Seriously Fish — Species profiles and care data
- FishBase — Taxonomy and scientific data
- Practical Fishkeeping — Husbandry and care advice
March 2, 2024
Algae Eaters for Betta Tanks: My 7 Picks After Years of Betta Keeping
I’ve kept bettas for years, and algae is something almost every betta keeper deals with eventually. My personal go-to has always been nerite snails. they’re peaceful, do an excellent job on algae, and won’t provoke even the most territorial betta. If the tank is big enough, I’d pair them with an Otocinclus catfish or two for extra coverage. The one thing most people overlook: once you start adding algae eaters, you’re moving into community tank territory. and tank size becomes more important than most people realize.
Key Takeaways
- The best algae eaters for Bettas are mystery snails and Otocinclus catfish
- Some fish are poor choices due to the betta’s aggressive nature or preference for warmer waters
- Make sure to supplement food with your algae eaters as it’s likely for them to starve without it
- Consider live plants if you want a more natural way to combat algae by having them outcompete outbreaks
What Is Algae?

Algae are plant like organisms that grow their food through photosynthesis. There are many types of algae and some of them are much easier to control than others!

Algae blooms are normal in new tanks that are still going through their first cycle. However, you can expect to see some algae in mature aquariums too.

There are many ways to control algae growth, ranging from manual scrubbing to growing live plants, but adding a few algae eaters is probably the most interesting method!

Increasing maintenance, limiting waste products, fish food, and reducing aquarium light duration are also effective techniques that can help you beat algae.

There’s a lot more to learn about aquarium algae! check out my guide to 10 types of aquarium algae (and how to get rid of them!) for more detailed information.

What You Need to Know About Temperment

Betta fish are known for their aggressive nature, but they don’t always deserve this reputation. Many aquarists keep their bettas with a variety of other fish without any problems, although there are always risks involved.

You see, betta fish were originally bred for fighting, so it’s no surprise that many individuals still have a mean streak. Some bettas are just more aggressive than others, and it has a lot to do with their own individual personality.

Tank size matters too, and upgrading to a larger aquarium can help to curb aggressive betta fish behavior. However, you should always have a backup plan in case your betta doesn’t get along with its new algae-busting friends.

⚠️ The biggest mistake I see: People try to add algae eaters to a 5 or 10-gallon betta tank without realizing they’re now running a community setup. The moment you add another inhabitant, tank size, filtration, and territorial behavior all become critical factors. My recommendation: if you want algae eaters with your betta, aim for at least a 20-gallon tank.

Go ahead and check out my guide to the 15 best betta tankmates to learn much more!

Algae Eater For Betta Tank – 7 Top Picks

There are many amazing algae eaters in the aquarium hobby, but these seven species are my top picks for your betta fish aquarium! Check out the video from our YouTube Channel and the additional details below from our blog post!

1. Octocinclus Catfish

Otocinclus Catfish

A small algae-eating fish. Also great with freshwater shrimp.

Click For Best Price
- Scientific name: Otocinclus sp.
- Difficulty: Moderate
- Adult size: 1.75 inches
- Minimum tank size: 10 gallons
- Temperature: 70 – 77 °F
- Algae types: Soft green algae and diatoms
Otocinclus catfish are about the smallest algae-eating fish in the hobby. These nano fish are also known as dwarf suckers for their habit of sucking onto aquarium glass, plants, and hardscape features.

Otos are extremely peaceful and make excellent algae eaters for betta tanks, although they are not the ideal choice for beginners or aquarists with small tanks. They can be kept in tanks as small as 10 gallons, although 15 gallons or larger would be better.

If your otocinclus catfish do their job a little too well and eat all the algae in their tank, you’ll need to supplement their diet with algae wafers and some soft greens like zucchini. They are social fish, so pick up a school of five or more.

2. Nerite Snail

Best Algae Snail

Horned Nerite Snail

Horned Nerite Snails are excellent algae eaters for planted tanks.

Click For Best Price Buy On Amazon
- Scientific name: Neritina spp., Vittina spp., Clithon spp.
- Difficulty: Easy
- Adult size: 0.75 – 1 inch
- Minimum tank size: 5 gallons
- Temperature: 70 – 80 °F
- Algae types: Soft green algae, diatoms, green spot algae
Nerite snails are the smallest algae eaters and the number one choice for small betta aquariums in the 5-gallon range. These hard-working mollusks are some of the best-looking inverts in the hobby, and they do a terrific job of cleaning algae in an aquarium.

Nerites breed in brackish water, so there’s no chance of finding any baby snails in your tank. However, they will lay a few eggs here and there. Most betta fish will get along great with nerite snails, but some aggressive fish will nip at nerites.

🏆 My personal pick: Nerites are the algae eater I reach for first in betta tanks. I’ve used them in my own setups for years. They work even in 5-gallon tanks, they won’t breed in freshwater, and most bettas leave them completely alone. If your tank is 20 gallons or larger, I’d add a couple of Otocinclus alongside them for even better algae control.

3. Mystery Snail
- Scientific name: Pomacea bridgesii
- Difficulty: Easy
- Adult size: 2 inches
- Minimum tank size: 5 gallons
- Temperature: 70 – 80 °F
- Algae types: Various
Mystery snails are large aquarium invertebrates that grow to about the size of a golf ball. They come in a variety of cool colors, making them an interesting display animal for your betta tank.

These snails will eat algae and uneaten food in the tank, so they’re great for keeping your tank clean. However, they are not as good at algae control as their smaller cousin the nerite. If you keep just one, you won’t have to worry about any unsightly eggs, although they can reproduce if you keep two or more.

Other snail species, like rabbit snails and ramshorn snails, are helpful for algae control, although you might want to avoid species like ramshorns and Malaysian trumpet snails if you don’t like the idea of breeding snails in your tank.

4. Bristlenose Pleco

Bristlenose Pleco

The Bristlenose Pleco is a smaller Pleco that does a great job of eating algae. Peaceful and gets along with most fish

Click For Best Price
- Scientific name: Ancistrus spp.
- Difficulty: Easy
- Adult size: 5 inches
- Minimum tank size: 20 gallons
- Temperature: 74 – 80 °F
- Algae types: Hair algae, cyanobacteria
Bristlenose plecos are excellent algae eaters for larger betta tanks of at least 20 gallons. They love to eat algae and graze on wood, so make sure there’s plenty of driftwood in the tank.

Full-grown bristlenose plecos may look kind of scary with their interesting bushy beards, but these fish are very peaceful with other species and they won’t bother your betta fish. On the downside, plecos tend to produce a lot of waste due to their vegetarian diet, so they need decent filtration and regular tank maintenance.

5. Molly Fish
- Scientific name: Poecilia sphenops
- Difficulty: Easy
- Adult size: 3-6 inches
- Minimum tank size: 20 gallons
- Temperature: 75 – 80 °F
- Algae types: Hair algae
Mollies are live-bearing fish that are surprisingly good at controlling algae! These hardy fish are peaceful but robust enough to hold their own against a grumpy betta.

However, mollies are one of the larger livebearers, so you’ll need an aquarium of at least 20 gallons to combine these two species. Mollies also need fairly hard, high-pH water, so they will not make good betta tank mates in soft, acidic conditions.

Mollies are very easy to breed, so you can expect loads of baby fish if you keep males and females together. Choose a couple of males only if you have limited space in your tank.

6. Hillstream Loach
- Scientific name: Sewellia lineolata
- Difficulty: Moderate
- Adult size: 2.5 inches
- Minimum tank size: 20 gallons
- Temperature: 64 – 80 °F
- Algae types: Soft green algae and diatoms
The hillstream loach is one of the most unusual freshwater fish in the aquarium hobby. These little guys look almost like tiny freshwater stingrays, and they love eating algae!

The hillstream loach is not the ideal tank mate for a betta fish, but you can make it work if you create an environment that favors both of these small fish.

These voracious algae eaters prefer well-oxygenated, cool water with a rocky bottom, but they can be housed with a betta if your water temperature is kept in the mid-70s Fahrenheit. Adding an airstone for increased oxygenation and water movement will make them feel right at home without creating too much current in the water.

7. Clown Pleco
- Scientific name: Panaqolus maccus
- Difficulty: Easy
- Adult size: 3 – 5 inches
- Minimum tank size: 20 gallons
- Temperature: 73 – 82 °F
- Algae types: Biofilm on driftwood
Clown plecos are not as effective as bristlenose plecos or otocinclus catfish, but their small size and peaceful nature make them great algae eaters for betta aquariums in the 20-gallon range.

These fish are helpful algae eaters that can effectively clean up a small aquarium, although they spend most of their time feeding on driftwood.

Others You Think Might Work, But Don’t!

The recommended species mentioned above are not the only aquarium fish and invertebrates that feed on algae, so you might be wondering why some of the other algae eaters didn’t make the list. Read on to learn why these seven species don’t make good betta fish tank mates.

1. Guppies and Endlers Livebearers

Keeping guppies with your betta fish can be pretty risky, especially if you have colorful male guppies with big flowing fins. Their similar appearance may trigger some aggressive responses from your betta, but guppies are also known to nip betta fins.

Guppies will feed on algae, although they don’t eat quite enough to keep a tank clean.

2. Platies

Platies are beautiful freshwater fish that can actually make good tank mates for your betta fish. Like guppies, these colorful livebearers are known to nip betta fins from time to time, but the main reason to avoid these active fish is their diet.

Platies can be good algae eaters, but they just aren’t as effective as something like an otocinclus catfish or a nerite snail.

3. Most Plecos

Plecostomus catfish are efficient algae eaters, although their size often turns into a problem. Most plecostomus catfish are simply too large to keep in a betta aquarium. Species like the common pleco can reach two feet in length, so adults require an aquarium that holds hundreds of gallons!

Stick to the bristlenose and clown plecos unless you keep your betta fish in a very large community tank.

4. Amano Shrimp

Male Shrimp

Amano shrimp are one of the best algae eaters for planted freshwater aquariums but they are not the best tank mates for a betta fish.

Unfortunately, betta fish tend to nip at these gentle crustaceans and they may even eat smaller specimens. Some betta fish will get along great with amano shrimp, but it’s just not worth the risk.

5. Cherry Shrimp

Adding cherry shrimp to your betta fish tank is probably not going to end well. Betta fish will eat these miniature invertebrates if they can catch them, so it’s really just a matter of time before these colorful shrimp disappear into your betta’s belly.

Unfortunately, the same goes for other shrimp species like ghost shrimp and young bamboo shrimp. If you would like to attempt keeping shrimp with your betta fish, my recommendation would be to start with a few ghost shrimp or feeder shrimp and see how your fish responds.

6. Siamese Algae Eater

Siamese algae eaters (SAEs) are avid algae eaters, but you should think twice before adding these active Asian fish to your betta tank.

Siamese algae eaters grow to 6 inches and they should always be kept in schools, so they need a much bigger aquarium than your average betta fish tank. Siamese Algae eaters also tend to stop eating algae as they mature, and they can get a little aggressive around feeding times.

7. Chinese Algae Eaters

The Chinese algae eater is not a smart choice for your betta tank because these freshwater fish can grow to over 10 inches in length and need a tank of at least 55 gallons for long-term care.

Even if you do keep your betta in such a spacious aquarium, there are more efficient and peaceful options for algae control.

Cleaner Fish

Some cleaner fish make great additions to a betta tank, although these helpful bottom feeders are not going to help with your algae problem. Many beginner aquarists assume that bottom feeders eat algae or that they do not need to be fed, but that’s not exactly true.

Cleaner fish will happily snack on any uneaten betta food that sinks to the bottom, although you’ll still need to feed them a healthy diet. The following cleaner fish can make great tank mates for your betta fish, just don’t expect them to do much about the algae.

1. Corydoras Catfish
- Scientific name: Corydoras spp.
- Difficulty: Easy
- Adult size: 1 – 3 inches (depending on species)
- Minimum tank size: 30 gallons for most species
- Temperature: 72 – 78 °F
- Diet: Omnivorous. Provide a sinking food such as a bottom-feeder tablet
Corydoras catfish, also known as cories, are gentle bottom dwellers that make great tankmates for betta fish. These schooling fish love to hang out at the bottom of the tank and search through the substrate for tasty morsels.

Cory catfish are social creatures, so it’s important to buy a school of 5 or more of the same species. Smaller cories are a better fit for most betta aquariums, but keep in mind that the smallest species (dwarf and pygmy cories) tend to hang out in the water column or on plant surfaces more than the bottom of the tank.

2. Kuhli Loach

Kuhli Loach

Kuhli Loaches are hardy bottom-dwelling fish. Nocturnal in nature. Gets along with many fish and tolerate of coldwater environments

Click For Best Price
- Scientific name: Pangio kuhlii
- Difficulty: Easy
- Adult size: 3 – 4 inches
- Minimum tank size: 20 gallons
- Temperature: 73 – 86 °F
- Diet: Omnivorous. Provide a sinking food such as a bottom-feeder tablet
Kuhli loaches are small, eel-like bottom dwellers that will search the substrate of your betta tank for uneaten food. These peaceful fish are mostly nocturnal, so you might not see them too much during the day.

Kuhli loaches are social fish, so you’ll need a small group of four or more. They will burrow into the sand or gravel of your tank, but be sure to add some hiding places like driftwood and rocks to help them feel secure during the day.

3. Whiptail catfish

View this post on Instagram

A post shared by Global Fish 🔌 (@globalfishcompany)
- Scientific name: Farlowella spp.
- Difficulty: Moderate
- Adult size: 4 – 6 inches
- Minimum tank size: 20 gallons
- Temperature: 72 – 79 °F
- Diet: Sinking foods and algae
The whiptail catfish is one of the strangest freshwater fish species, but also one of the most peaceful. These camouflaged fish look just like a twig, which helps them stay hidden from predators in the wild.

Whiptail catfish are actually good algae eaters in their own right, although you’ll need to supplement their diet with sinking foods like tablets and wafers.

Other Techniques for Controlling Growth

Algae eaters can be extremely helpful for cleaning up your betta aquarium, although they are not the only option. Serious algae growth is usually a symptom of an imbalance of light and nutrients and there are a few steps you can take to control this pesky stuff if you have an aggressive betta that doesn’t want to share their tank.

Try these four techniques for controlling algae growth:

1. Cut the lights

Algae tend to thrive in high-light situations, especially if there are plenty of nutrients in the water. Make sure your betta tank is not exposed to any direct sunlight.

Powerful aquarium lights will also benefit algae, so use a timer to maintain a regular lighting schedule of about 6 hours or so each day.

2. Grow Live Plants

Live plants look great and create and healthy home for your betta fish. However, their true benefit lies in their algae-fighting abilities!

Healthy live plants effectively compete with algae and help to soak up excess nutrients in the water, so growing a few fast-growing stem plants can really help with persistent algae problems. However, dead plant matter actually decreases water quality, so take good care of your plants and fertilize them regularly.

3. More Maintenance

Poor water quality with high nitrate levels is a common cause of algae blooms. Test your tank water and perform regular water changes to keep your nitrate levels down to 20 parts per million or less.

You can also clean and remove algae manually during your maintenance routine. Grab your algae scraper and clean the glass before sucking water out of the tank with your gravel vacuum. A toothbrush works great for cleaning ornaments, rocks, and driftwood.

4. Reduce Feeding

Excess nutrients from over-feeding fish is one of the leading causes of poor water quality and excessive algae growth. Feed your betta fish once or twice a day and watch to see that your pet is finishing all the food. Uneaten pellets or granules that sink to the bottom will go to waste and increase nitrate and phosphate levels.

Can you have an algae eater with a betta?

There are many good algae eaters in the hobby that can live with betta fish, although it’s important to select a species that will be happy in your aquarium. Most algae-eating fish need a tank of at least 20 gallons, so snails may be the best choice if you have a small tank.

How do I get rid of algae in my betta tank?

Algae eaters are a great way to manage excess algae, although you can also remove algae manually when cleaning your tank.

Film algae can be removed from the tank glass with an algae scraper, while soft algae on the substrate can be sucked out with your gravel vacuum. Remove tougher algae on your hardscape with a small brush.

What is the best bottom feeder for a betta fish tank?

Corydoras catfish and kuhli loaches are some of my favorite bottom dwellers for large betta fish tanks. Malaysian trumpet snails are a good option for small tanks, although many aquarists prefer to avoid these inverts as they tend to multiply fast in nutrient-rich environments.

Can you put a betta with a plecostomus?

Plecos are good algae-eating fish for larger betta aquariums, although it’s important to choose the right species. Smaller species like the bristlenose and clown plecos are ideal for tanks of 30 gallons or more. Avoid larger varieties like the common pleco and sailfin pleco unless you have a very large fish tank.

How do I control algae in my betta tank?

Excess light and nutrients are common causes of algae, so make sure you aren’t feeding your fish too much, and avoid positioning your tank in direct sunlight or leaving your tank lights on all day. Good filtration, frequent maintenance, and regular water changes are also vital for keeping a clean tank.

Final Thoughts

Algae eaters and bottom dwelling fish are fascinating creatures that can help to keep your betta aquarium looking cleaner for longer. However, you should take your time before choosing your betta clean-up crew and make sure each species will live happily in your tank size and water parameters.

Have you kept algae eaters in your betta fish aquarium? Share your favorite species in the comments below!

📘 Want to learn more? This article is part of our complete Betta Fish Guide. your ultimate resource for betta care, types, tank setup, feeding, tank mates, and more.

🌿 Want to learn more? This article is part of our complete Planted Tank & Aquascaping Guide. your ultimate resource for aquarium plants, aquascaping styles, substrates, and more.

References
- Seriously Fish — Species profiles and care data
- FishBase — Taxonomy and scientific data
- Practical Fishkeeping — Husbandry and care advice
February 26, 2024
Vegetables for Fish: What I Feed My Tanks After 25 Years (And What to Avoid)
I’ve been feeding vegetables to my fish for years. Nori sheets for saltwater tanks, and cucumbers and romaine lettuce for freshwater setups. It’s one of the most underrated things you can do for herbivorous and omnivorous fish, and once they find it, they go for it every time. One critical step most people skip: blanching. Leave it out and you risk fouling your water with pesticide residue and disintegrating plant matter. This guide covers what actually works, what doesn’t, and how to prepare it correctly.
Key Takeaways
- Aquarium fish can be given an assortment of raw and frozen vegetables!
- Veggies are a great way to keep fish healthy by introducing vitamins and minerals that aren’t offered in typical fish food.
- Vegetables can be easily blanched and frozen for easy storage and long-term use.
- Some fish don’t like vegetables or have never been offered them, so algae wafers are a good alternative instead!
Vegetables For Fish – Which Are The Best Ones?

The best vegetable to feed fish (video from our official YouTube Video) is one that will withstand being submerged, at least for an hour or two. This vegetable should not start to disintegrate once a hungry fish starts to get to it. Luckily, a variety of vegetable options can be blanched and eaten by fish.

A good list of rotating veggies might look like:
- Broccoli
- Cucumber
- Zucchini
- Yellow squash
- Spinach
- Romaine lettuce
- Carrot
- Peas
- Nori (great for saltwater fish)
Not all fish will like all vegetables, so it might take some time to figure out which ones to include in your feeding rotation. Most hobbyists like to weigh small pieces down with a rubber band around a rock or a suction clip that attaches to the side of the glass.

🏆 My personal picks: For freshwater tanks, cucumbers are my go-to. fish love them, they hold up well submerged, and they’re easy to prep. For saltwater, Nori (dried seaweed sheets) is the clear winner. tangs and rabbitfish will go absolutely crazy for it on a clip. I’ve also had great results with romaine lettuce in freshwater setups.

Does Your Aquatic Pal Need Them?

Before we even start to discuss how to prepare fresh vegetables for your fish, you need to know if these foods would be similar to something that they would naturally come across in the wild. A carnivorous fish will probably not eat a cucumber, no matter how appealing it might look!

Most likely, you won’t be able to tell whether a fish is a carnivore, herbivore, or omnivore just by looking at it. There might be some signs, like sharp teeth or a sucker mouth, but even then, you can’t be fully sure. The best way to find out the natural diet of your fish species is by doing research about their natural habitat and hearing experiences from other hobbyists or your local aquarium store.

Once you’ve established the natural diet of your fish, you can begin catering to it. If it turns out that you have a herbivore fish, then you might start to supplement blanched vegetables into their diet.

Benefits of Veggies

There are many benefits to giving vegetables to fish. The main benefit is keeping fish healthy by supplementing vitamins and minerals that aren’t supplied through typical fish food¹.

The other main benefit is enrichment. By now, you’ve probably noticed that your fish waits to be fed at the top of the aquarium anytime you walk by. Feeding time is what they look forward to! Adding veggies is a great way to make feeding time even more exciting and unpredictable while also adding variety and balance to your fish’s diet.

What Are Blanched Vegetables?

Simply put, blanching means submerging vegetables or fruits into boiling water for a short period, quickly removing them, and then placing them into a bowl of water with ice. This process only takes a couple of minutes but helps preserve the quality of the vegetable or fruit.

There are a few ways blanching achieves preservation. First, it inactivates enzymes that would otherwise begin to affect color, taste, and nutritional value over time. Similarly, blanching affects bacteria which would also cause the product to degrade faster.

Blanching is especially recommended when using vegetables as fish food due to insecticides and other residues. Unfortunately, many unknowns are used to treat food for consumption, so boiling them first reduces the chances of those chemicals entering the aquarium.

⚠️ The biggest mistake I see: People skip blanching entirely. Raw, unblanched vegetables can foul your water fast as they break down, and you’re putting pesticide residue directly into your tank. Blanching takes about two minutes and makes a real difference. don’t skip it.

All in all, blanching fresh fruits and vegetables helps preserve them for longer and allows for easy freezing and storage. In the aquarium setting, most hobbyists only offer vegetables as fruits can be messy.

Can You Serve Them Raw?

Yes! Tropical fish can be fed raw vegetables. Blanching is recommended for hobbyists who want to keep vegetables on hand for future use. There are a couple of things that need to be considered, though.

As mentioned before, veggies are often treated with chemicals and other preservatives. These should be thoroughly washed off before being added to the tank. It is also likely that these pieces of raw vegetables will end up floating on the surface of the water, so it might take some extra effort to weigh them down.

How To Blanch Them

Almost any vegetable can be blanched, but not every blanched vegetable is good for the aquarium. Instead, certain hard vegetables, like broccoli, cucumber, zucchini, and peas, are some of the favorite feeding options for herbivores. This is because other vegetable matter can easily break down and start to affect water quality.

Vegetables with strong aromas, like brussels sprouts and onions, should be avoided as they can start to affect water conditions as well.

Buying Them

This might seem obvious, but you need to purchase your vegetables at the grocery store. Your local fish store will not have fresh vegetables! Now the question comes down to picking the right veggies for your fish.

Should you buy organic?

You definitely want to pick the best vegetables possible to feed your fish, and you should be mindful of what you’re putting in the aquarium. However, there is likely little difference between buying organic and using regular produce. The blanching process should hopefully remove any chemicals or additives in either option.

If you want to feed raw cucumber or another vegetable fresh from the rack, then it may be the better choice to buy organic.

Preparation

Depending on what type of vegetables you get for your fish, you might need to do some prep work. Think about how much food you want to give to your fish, for how long, and if you could use the leftovers for your own consumption!

Some vegetables, like zucchini, cucumber, and broccoli, will need to be cut up into manageable pieces. The goal should be to slice to expose as much of the soft, inside flesh as possible as fish will likely eat these sections first. For something like zucchini, slice each piece to be about 0.5 inches. Most other vegetables, like spinach and lettuce, can be split apart and fed more easily.

Now, you will want to consider how long you want to serve your fish this food. Fish eat as much as is available, so it’s not recommended to give it all at once. But you don’t want to be feeding the same thing for a month either! Prepare enough food for several feedings. Save some for blanching and save some for the dinner table.

Blanching Steps

Now it’s finally time to blanch the veggies. This process is straightforward and easy and almost impossible to mess up.
1. Bring a pot of water to a rolling boil. The boiling water will activate those processes we talked about earlier!
2. Fill a separate bowl with water and ice.
3. Add the sliced vegetables to the boiling water.
4. Allow them to boil for 1-3 minutes depending on the size of the slices.
5. Remove the vegetables when they’re crispy. A crunchy vegetable needs more time and a mushy vegetable has gone too long.
6. Add the veggies to the ice bath. Let them sit in the cold water for a minute or two.
7. If you’re planning on freezing the vegetables, then wait until they’re completely cooled and dried. Then, store them in a plastic bag in the freezer.
Feeding Your Fish

When you’re ready to feed your fish, make sure to fully thaw the frozen vegetable matter. You may need to weigh it down with a rock or clip so that it doesn’t float.

View this post on Instagram

A post shared by Jakob Levi Walsh (@negativerail)

Allow your fish to eat. It might take some time for them to find and understand that the vegetable matter is food. Snails are also naturally slow!

After a couple of hours, remove what remains of the veggies. If your fish and snails liked what they were given, you might just find vegetable skin left over.

How Often To Feed Vegetables?

How often you feed your fish fresh or frozen vegetables will depend on how many fish are present and their feeding habits.

If you have a larger tank with lots of tropical fish, shrimp, and snails, then you will need more food to make sure that everyone is getting fed. Always make sure to keep an eye on uneaten food and remove any pieces that could potentially get stuck in the back of the tank.

In general, fresh and frozen vegetables can be given one to two times a week to create a well-balanced diet.

Alternatives

While most aquarium fish enjoy a veggie snack every now and then, some fish simply don’t like vegetables, even if they’re herbivores.

It makes sense why a carnivorous fish might not eat veggies, but why wouldn’t a herbivore?

It is possible that your fish was never introduced to any foods other than flake or pellet foods. They might not know how to eat veggies! In cases like this, you can continue to offer your fish fresh vegetables until they take a nibble, or you could settle with a high-quality algae wafer or pellet.

For saltwater fish, consider a product like Julian Sprung’s Sea-Veggies

Great For Algae Eaters

Sea Veggies Seaweed Green

Sea veggies is an amazing product for Tangs, Rabbitfish, and Marine Angelfish. Fish go crazy for it. Clean and easy to feed!

Click For Best Price Buy On Amazon

FAQs

What vegetables can I feed my fish?

Tropical fish love most vegetables! But every fish will have its own appetite. The best veggies to feed fish include lettuce, peas, zucchini, and cucumber. These can be given raw or frozen as long as they are prepared and thawed before serving.

Can I feed my fish fruits?

While fruits can be blanched and stored for serving later, it’s not recommended to give fruits to fish. This is because fruit is high in sugar, which can easily start to affect aquarium water. Because of this, it’s generally recommended to only give fish vegetables.

How do I make prepared fish foods?

Feeding vegetables to fish is quick and easy! Depending on the type of veggie you’re giving, you may need to cut it up into small pieces. These pieces can then be washed and added directly to the tank or blanched and saved for later.

Why didn’t my fish eat vegetables?

Every fish is different and yours might not enjoy vegetables! Instead, you can supplement those vitamins and minerals with algae wafers or pellets.

How do I make prepared fish foods?

Feeding vegetables to fish is quick and easy! Depending on the type of veggie you’re giving, you may need to cut it up into small pieces. These pieces can then be washed and added directly to the tank or blanched and saved for later.

Why didn’t my fish eat vegetables?

Every fish is different and yours might not enjoy vegetables! Instead, you can supplement those vitamins and minerals with algae wafers or pellets.

Can saltwater fish eat vegetables?

Yes! Saltwater fish can also be given vegetables even though they’re unlikely to experience plant matter in their natural habitats. Because of this, saltwater fish are more likely to ignore vegetable offerings, but some might take a nibble.

Instead, saltwater fish can be offered different types of macroalgae and seaweed sheets. The most common type of veggie before Nori was popular was romaine lettuce.

Conclusion

Most fish love a selection of fresh veggies in addition to their staple fish flakes or pellet, though some fish don’t! These vegetables can be served raw or blanched and frozen for later use. Some options include lettuce, peas, carrots, and broccoli, but an algae wafer will substitute for more picky fish.

Keep in mind that feeding fresh veggies can be messy and not all fish will enjoy the offer! Uneaten food should be removed if left untouched after a couple of hours.

🐟 Want to learn more? This article is part of our complete Aquarium Care Guide. your ultimate resource for water chemistry, maintenance, feeding, disease prevention, and everything you need for a healthy tank.
February 24, 2024