Author: Mark Valderrama

After 25 years in the hobby, I’ve introduced a lot of people to fishkeeping — and the fish you start with makes a huge difference in whether you stick with it. Easy fish don’t mean fish that thrive in neglect. They mean fish that forgive the inevitable beginner mistakes: a temperature swing, a slightly delayed water change, a new tank that isn’t perfectly cycled. The 12 fish on this list are the ones I’d actually recommend to someone starting out — hardy, adaptable, and interesting enough that you won’t outgrow them once you have more experience.

12 Simple Species To Take Care Of

Now that you know more about the benefits of keeping low-maintenance fish, it’s time to dive straight in and meet 12 awesome fish species you can keep!

Check out this video below from our YouTube channel. We go over more detail in the blog post below.

Each species profile includes a list of important facts, so take note of the following:

• Scientific name
• Temperament
• Origin
• Size
• Minimum Tank Size
• Diet
• pH
• Temperature
• Difficulty to breed

1. Betta

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Betta Fish are one of the most beautiful varieties of freshwater fish available in the hobby. Easy to care for with plenty of varieties!

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• Scientific name: Betta splendens
• Temperament: Aggressive
• Origin: Southeast Asia
• Size: 2.5 inches
• Minimum Tank Size: 5 gallons
• Diet: Feed granules, pellets, flakes, brine shrimp & blood worms
• pH: 6.5-7.5
• Temperature: 75-82°F
• Difficulty to breed: Moderate

The good old betta fish is a great species to start our list with. Betta fish are also called Siamese fighting fish because if you keep more than one male in the same tank, you can expect a war!

These colorful fish make great beginners fish because they don’t need a large fish tank and they’re really fun to keep. Betta fish can be kept with other community fish, but many beginners prefer to keep one of these beautiful tropical fish in its own tank.

2. White Cloud Minnows

White Cloud Mountain Minnow

A very peaceful fish that does well in coldwater fish. Other minnow varieties are also available

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• Scientific name: Tanichthys albonubes
• Temperament: Peaceful
• Origin: China
• Size: 1.5 inches
• Minimum Tank Size: 10 gallons
• Diet: Feed granules, pellets, flakes
• pH: 6-8.5
• Temperature: 58-72°F
• Difficulty to breed: Moderate

The peaceful white cloud minnow is not actually a tropical fish. This means they don’t necessarily need a heater unless your home is really, really cold. These cold-water fish have great colors and they’re very peaceful, making them awesome fish species for beginners!

White cloud minnows don’t need a big tank, and they get along great with other fish. Just remember that these fish like it a little cooler than many other fish.

3. Danios

• Scientific name: Brachydanio rerio etc.
• Temperament: Peaceful
• Origin: Asia
• Size: 1.5-5 inches
• Minimum Tank Size: 15-30 gallons
• Diet: Feed pellets, granules, flakes, and live/frozen foods
• pH: 6-8
• Temperature: 65-77°F
• Difficulty to breed: Moderate

There are loads of beautiful danio species in the aquarium trade, and many of them are perfect beginner fish! Zebra danios are a great example, and they’re usually very easy to find.

These active little fish also come in spotted (leopard) and long-finned forms. Zebra danios are really peaceful and super hardy fish, but give them a nice big tank because they do prefer plenty of room to swim.

4. Endler’s Livebearer

Endler's Livebearers

A very active and colorful livebearer. Smaller in size than guppies

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• Scientific name: Poecilia wingei
• Temperament: Peaceful
• Origin: South America
• Size: 1.5 inches
• Minimum Tank Size: 10 gallons
• Diet: Feed granules, pellets, flakes
• pH: 7-8.5
• Temperature: 75-86°F
• Difficulty to breed: Easy

The Endler’s livebearer is similar to a regular guppy, but they stay even smaller. These fish are super easy to care for, and they have amazing colors too!

These very small fish are called livebearers because the females give birth to live baby fish instead of laying eggs. They are one of the easiest fish to breed, but if you prefer not to have loads of tiny fish in your tank, go ahead and pick up just males, or just females. If you want to go larger, you can try platys or molly fish.

5. Kuhli Loach

Kuhli Loach

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

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• Scientific name: Pangio semicincta
• Temperament: Peaceful
• Origin: Southeast Asia
• Size: 3.5-4 inches
• Minimum Tank Size: 15 gallons
• Diet: feed sinking tablets and frozen foods
• pH: 3.5-7
• Temperature: 70-79°F
• Difficulty to breed: Advanced

Kuhli loaches are super hardy and super easy to care for. They prefer to come out after dark, and they’re pretty shy, so I wouldn’t recommend these guys if you’re only looking for only one species.

For a community tank, however, kuhli loaches are great because they are always willing to pick up any scraps of uneaten food and help keep your aquarium clean.

6. Bristle Nose 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

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• Scientific name: Ancistrus spp.
• Temperament: Peaceful
• Origin: South America
• Size: 5 inches
• Minimum Tank Size: 30 gallons
• Diet: Feed sinking tablets, algae wafers, and plant material
• pH: 6.5-7.4
• Temperature: 70-78°F
• Difficulty to breed: Moderate

The bristle nose pleco is a really cool-looking bottom-dweller fish that is very easy to keep. These small fish are also known as the bushy nose pleco because males develop strange bushy growths on their faces.

Bristle nose plecos are suckerfish, and they love eating algae off driftwood and the glass walls of the aquarium. There are both the regular and albino varieties available.

7. Harlequin Rasbora

Harlequin Rasbora

A peaceful schooling fish. An ideal community fish. A great beginner fish

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• Scientific name: Trigonostigma heteromorpha
• Temperament: Peaceful
• Origin: Southeast Asia
• Size: 1.25-1.75 inches
• Minimum Tank Size: 15 gallons
• Diet: Feed granules, flakes, and frozen/live foods
• pH: 5-7.5
• Temperature: 70-82°F
• Difficulty to breed: Moderate

The harlequin rasbora is a really good beginner fish. These reddish schooling fish have great triangular markings on their sides, just like the shape of a pork chop!

Harlequin rasboras are very easy fish to keep, and they love to have live plants in their tanks. They get along really well with other fish species too, but they should not be kept with more aggressive fish.

8. Albino Corydoras Catfish

• Scientific name: Corydoras spp.
• Temperament: Peaceful
• Origin: South America
• Size: 2-3 inches
• Minimum Tank Size: 15-30 gallons
• Diet: Feed pellets, tablets, and live/frozen foods
• pH: 7-8
• Temperature: 74-80°F
• Difficulty to breed: Advanced

Cory catfish are some of the best beginner fish in the hobby, and albinos are especially cool. These brightly colored little catfish are always easy to find, and they are very hardy. These neat little bottom feeders get along with all other peaceful fish, and they love picking up scraps at the bottom of the tank.

Like siamese fighting fish, cory fish breathe atmospheric air, so don’t be surprised to see them shoot up to the surface to take a breath every now and then!

9. Cherry Barbs

Cherry Barb

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

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• Scientific name: Puntius titteya
• Temperament: Peaceful
• Origin: Sri Lanka, Asia
• Size: 1.5-2 inches
• Minimum Tank Size: 15 gallons
• Diet: Feed granules, pellets, or flakes. Include some plant matter and live/frozen food
• pH: 6-8
• Temperature: 68-81°F
• Difficulty to breed: Moderate

Cherry barbs don’t quite live up to the bad reputation of some of the other barb species. These peaceful and interesting schooling fish are great for beginners because they are very low maintenance and thrive in a wide range of temperatures and water parameters. Cherry barbs are a great-looking fish species too, and the males are especially colorful fish.

10. Red Eye Tetra

• Scientific name: Moenkhausia sanctaefilomenae
• Temperament: Peaceful
• Origin: South America
• Size: 2.8 inches
• Minimum Tank Size: 20 gallons
• Diet: Feed granules, pellets, or flakes. Include some plant matter and live/frozen food
• pH: 6-8
• Temperature: 72-79°F
• Difficulty to breed: Moderate

The good old red monk or red-eye tetra is a very underrated freshwater fish that is perfect for beginner fish keepers. They grow a little larger than other common species like the neon tetra, so set them up with a nice big tank and plenty of swimming space.

Red monk tetras are very peaceful, hardy, and active fish. They are social creatures too, so it’s important to keep them in a school of at least 6 of their own species.

11. Siamese Algae Eater

Siamese Algae Eater

A great algae-eating fish that is known for eating black beard algae. Grows up to 7 inches in length and requires a larger aquarium

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• Scientific name: Crossocheilus oblongus
• Temperament: Peaceful
• Origin: Southeast Asia
• Size: 6 inches
• Minimum Tank Size: 20 gallons
• Diet: Algae
• pH: 6.5-8
• Temperature: 75-79°F
• Difficulty to breed: Advanced

Siamese algae eaters are pretty large but very peaceful fish. They are amazing for keeping your tank clean because they love to eat algae. These tropical fish might not be very colorful, but they have a cool body shape, almost like a shark!

12. Black Neon Tetra

Black Neon Tetra

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

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• Scientific name: Hyphessobrycon herbertaxelrodi
• Temperament: Peaceful
• Origin: Brazil
• Size: 1.5 inches
• Minimum Tank Size: 15 gallons
• Diet: Feed granules, flakes, and live/frozen foods
• pH: 5-7.5
• Temperature: 68-82°F
• Difficulty to breed: Moderate

Black neon tetras are super hardy freshwater aquarium fish that are the perfect fish for beginners! They are completely peaceful tetras and get along really well with other species and tank mates.

Black neon tetras are naturally schooling fish, so make sure you pick up a group of at least 6 to really enjoy their natural behaviors.

Varieties To Avoid

Now that you know 12 of the best freshwater fish for a new aquarium owner, let’s take a minute to look at a few species to avoid. Now, these are all great fish, but they are a little better suited to more experienced fish keepers.

1. Goldfish

Many people think goldfish are for beginners, but this isn’t actually true. These fish come in loads of fancy goldfish varieties, but they are all the same species as regular goldfish.

Goldfish are coldwater fish so they definitely won’t be at home in your standard tropical community tanks. Goldfish also grow larger than many people think. At up to 6 inches, goldfishes produce a lot of waste, oh and they love to eat your live plants too!

2. Cichlids

Cichlids tend to be aggressive and territorial fish. The African cichlids can be very aggressive and they usually need hard, alkaline water to be healthy. Large South American cichlids like oscar fish need loads of space, and they can be very aggressive too.

Some species, like angelfish, are pretty easy to keep, but as a general rule, cichlids should be avoided if you’re just starting out.

3. Freshwater Sharks

Freshwater sharks, like bala sharks, are another popular group of tropical fish that are not great for beginners. These fish aren’t actually true sharks, but they have a very similar shape.

Freshwater sharks can get really big, and some of them tend to get a bit mean towards other fish.

Why Choose Easy Fish?

When you’re starting out, it’s best to choose the easiest fish to take care of. Here’s why:

Your Enjoyment

Keeping fish should be fun! Keeping low-maintenance fish allows you to spend more time enjoying your pets.

Even easy fish need good care and regular maintenance, of course, but fish keeping shouldn’t feel like too much hard work, especially if you’re just getting started.

Time And Budget

You probably don’t have the time to be caring for your fish for hours every day. Costs can also add up pretty quickly when you start getting into the more advanced fish species.

So do yourself a favor and start out with a manageable aquarium with easy fish. You’ll enjoy the hobby so much more. Besides, you can always set up more tanks in the future!

The Health And Well Being Of Your Pets

Easy fish are much safer for beginner fish keepers because they are less likely to get sick. Of course, you want your pets to live long and healthy lives, so set yourself (and your fish) up for success with some easy and hardy beginner fish.

What Makes Some Fish Easy?

Why are some fish easier to keep than others? They’re all fish, right? Well, not quite…

Some species of fish are just much easier to keep than others! Let’s take a look at why:

Tank Size

Smaller fish aren’t necessarily easier to keep than big ones. Small aquariums can be a lot easier to set up and maintain, however. A massive aquarium is a very heavy thing, that needs careful planning to set up safely. Water is heavy, and performing water changes and keeping a large tank clean can be quite a lot of work.

This doesn’t mean you should go out and get a tiny aquarium, however. Very small tanks are difficult to manage too because the water parameters can swing so quickly. A tank of 20 to 30 gallons is a great size to start out with.

Water Quality

Easy fish are a little more forgiving when it comes to changes in water quality. If you’re just starting out, there’s a good chance you’ll make a mistake here and there. Easy fish are more likely to survive mistakes, but of course, you should always strive to keep your water quality as high as possible.

Parameters

Some fish need very specific water parameters to stay healthy. Maintaining these parameters can be tough. The easiest fish to take care of are adaptable to a wider range of conditions and parameters.

Diet

Some fish need really specific diets. Providing them with the fish food they need can be expensive, or take a lot of planning and effort. Fish that are easy to feed are much easier to keep.

Temperament

Peaceful fish are so much easier and less stressful to keep than aggressive species. Nobody wants their pets to fight and hurt each other, so choosing peaceful fish definitely makes for easier fish keeping.

Caring for Freshwater Varieties – A Crash Course

Keeping a beautiful fish tank full of healthy aquarium fish takes some careful research and solid planning. In this section, I’ll give you some good general information and tips about setting up your first fish tank.

Let’s get started!

Aquarium Set-Up Checklist

Before you can buy your first freshwater fish, you’re going to need to set up a great freshwater tank where they can live. These are the basic components of any fish tank setup:

Aquarium (with hood)

You’ll need to put your tank on a strong and perfectly level surface. A stand or cabinet is best for larger tanks.

Filter

This is really important for keeping your water clean and healthy. Buy a model that is rated to your tank size or larger.

Heater

This is very important for keeping your water temperature safe for tropical fish species. You’ll need a heater that matches your fish tank size, and be sure to adjust it to the perfect temperature for your fish.

Lighting

Your fish need a regular day/night cycle, but your tank should never be exposed to direct sunlight. Fluorescent or LED lamps with a timer are ideal.

Substrate

This is the aquarium-safe gravel or sand at the bottom of the tank. Fish tend to prefer darker colors, but you can choose the color that you like best!

Additional Items

Once you have put together a basic fish tank, you’re almost ready to go! There are a hundred and one other things that are used in aquariums, but you probably won’t need them yet. Nevertheless, there are still a few really important items that you’ll need to keep your fish healthy and your aquarium looking great.

Make sure you have all of the items on this list to get started in the right way!

Decorations

Decorations make empty fish tanks come to life! Fish love them too because they create hiding places and structures that the fish can swim around. Choose driftwood, natural stone, and a few cool ornaments to create a beautiful aquarium.

Water test kit

Test kits allow you to measure important water parameters like pH and nitrates that you can’t see or feel. This is very important for keeping your fish safe and healthy.

Water conditioner

Tap water usually contains harmful chemicals like chlorine. Water conditioner neutralizes these chemicals and makes the water safe for freshwater fish. A solution like Seachem AI Prime works great!

My Pick

Seachem Prime

Seachem prime is a easy to use and affordable choice when it comes to remove chlorine and chloramines from your tap water. Highly recommended!

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Gravel vacuum and algae scraper

These two tools make keeping your substrate and glass clean much easier! You can use your gravel vacuum to suck up waste while you remove water for your regular water changes. An algae scraper helps you to remove stubborn algae without scratching your aquarium glass.

Thermometer

Use your thermometer for measuring the water temperature in your aquarium. It will also come in handy when preparing new water for a partial water change.

Weekly Maintenance And Care Schedule- Your To-do List!

Keeping your fish healthy and your tank looking great takes a little work. Here’s what you’ll need to do:

• Before bringing your fish home, make sure to cycle your tank to get the water ready. You’re going to need a little patience because this can take days or even weeks to do. It will all be worth it when you introduce your new fish into their awesome new home!
• Once your fish are settled in, you’ll need to test the water regularly to keep an eye on nitrate levels in the tank. It’s time to do a water change when the levels get over about 20 ppm (parts per million).
• Water changes might need to be done every week, every second week, or only once a month. It all depends on your fish and tank setup.
• Change out about 15-30% of your aquarium water when necessary. Use conditioned water that is the same temperature as your aquarium.
• Make sure to suck up all the waste at the bottom of your tank with your gravel vacuum. You can also clean your glass if necessary.

Feeding Your Tropical Companions

Your fish need a healthy, balanced diet to live a full life and look their best. Most fish do great on a regular diet of dried foods. The most common types of prepared foods are:

• Fish flakes
• Granules
• Pellets
• Wafers
• Sinking tablets
• Gel foods
• Freeze-dried food
• Frozen Food

Providing your fish with frozen or cultured live foods once a week or so will keep them in great condition, and they’ll love it too! These are the best options:

• Brine shrimp
• Blood worms

Overfeeding is a very common mistake, and it can make your aquarium water unsafe and even make your fish sick. You can feed your fish once a day, or provide small amounts of food two or three times a day.

To be safe, only feed your fish as much food as they can completely finish in a few minutes. That way, nothing goes to waste!

Where To Buy For Beginners

You can find most, if not all of the great fish on this list at most fish stores and pet stores. Chat to the sales people at the store to learn more about how they care for their fish and what food they provide.

If your local pet store doesn’t have what you’re looking for, you can always order your favorite fish online. Buying from a trusted online source couldn’t be easier, and your fish and aquarium supplies will be delivered safely to your door!

FAQs

Final Thoughts

Choosing the right freshwater aquarium fish when starting out can make all the difference. Fortunately, many amazing exotic species are easy to care for. Choose from this list of fish for beginners to start your very own amazing freshwater aquarium!

Which is your favorite easy freshwater aquarium fish? Let us know in the comments below! And check out our videos on our YouTube channel as we build our video library up!

📘 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.

Oscar fish are one of those species I always hesitate to recommend to new hobbyists — not because they’re difficult to keep, but because people seriously underestimate how large they get and how much waste they produce. I’ve seen too many oscars end up in tanks that are way too small. When you set them up correctly though, they’re one of the most interactive, personality-driven fish you can keep in freshwater. This guide covers all 8 types and what you need to make them thrive.

Oscar fish are one of the most rewarding freshwater fish you can keep — and one of the most commonly mistreated. I’ve seen it countless times: someone buys a cute 3-inch oscar at the store and doesn’t realize it’s going to hit 12 to 14 inches and need at least a 75-gallon tank by itself. Oscars are also genuinely intelligent — they recognize their owners, beg for food, and have distinct personalities. That interactivity is exactly what makes them so popular. But they’re messy, aggressive toward smaller fish, and demand serious filtration. If you go in prepared, they’re incredible. Here are 8 types of oscar worth knowing about.

Introduction to Oscar Fish

Oscar fish are a longtime favorite in the aquarium hobby and one of the most popular freshwater fish period. These fish are big, colorful, and full of personality. So much so that they have been nicknamed the aquarium puppy or river dog by some due to their extremely playful behavior.

Like other popular freshwater fish, the oscar fish has been subjected to improper care by beginner and inexperienced hobbyists. Many first-time oscar owners are not aware of their true size and just how quickly they will outgrow a tank. If given the right care, these fish can fill a larger tank all on their own.

The most popular type of oscar fish is the traditional orange and brown combination of the tiger oscar, but there are many varieties available for the more adventurous hobbyist.

Oscar Fish Care Requirements

Oscar fish are not impulse buys. They require long-term planning in regards to tank size, tank mates, and diet. Unfortunately, these fish are commonly sold as juveniles when they’re only a couple of inches big, tricking unknowing hobbyists about their true care requirements.

The truth is that Oscars are monster fish that not many hobbyists have the ability to care for. However, if you’re willing to give a very large tank to one single fish, then the oscar fish might be the best choice.

Their Natural Habitat

Oscar fish are scientifically known as Astronotus ocellatus. They are a type of cichlid though they’re not as aggressive as some of their closest relatives.

Instead, these gentle giants scour the basin of the Amazon River basin in South America for whatever can fit in their mouths. They have been documented in most countries throughout South America, but have known established populations in the United States as well as Singapore.

These ecosystems are heavily forested with a silt substrate. They prefer slow-moving rivers and tributaries with various structures, like tree limbs, where they can hide and claim territory. Oscars can be found living solitary lives or in small groups.

Tank Requirements

In terms of fishkeeping, oscar fish are just another type of South American fish from blackwater conditions. However, their mature size is what makes them difficult to keep.

Most oscar fish will surpass 1 foot in length at their mature size. In the store, they’re usually sold while they’re still small, which makes more hobbyists willing to buy them; this is a mistake as they’re put into a holding tank that they’ll grow out of with a promised upgrade in the near future. Most times, they’ve never actually given a bigger tank after that and the fish needs to be rehomed.

The bare minimum tank size for any type of oscar fish is 75 gallons. A 125 gallon tank is even better to allow for more swimming space and more controllable water parameters.

This tank should be given a powerful filter to keep up with the messy habits of oscar fish. Additional flow is not needed and lighting can remain dim. They prefer a sandy bottom and will enjoy rummaging through it for additional food to eat; this also means that live plants are not safe from being uprooted!

Otherwise, oscar fish tank setup is simple. Add some rocks and driftwood for shelter and your oscar will thrive.

What Is The Biggest Type?

We mentioned before that oscars are monster fish and can easily surpass a foot at adult size. But how big can they actually get and are the different types of oscar fish different sizes?

The biggest that oscar fish can get to be in captivity is about 18 inches and several pounds. It is rare for them to get any bigger than this, though they can keep growing over their 20 year lifespan.

Most types of tiger oscar that were derived from Astronotus ocellatus have the ability to reach these monstrous sizes. Some breeders have made short-bodied varieties that may stay slightly smaller, though.

Temperament

If oscar fish are known for one thing, it’s their personalities. These fish are full of life and will let you know when they don’t like something in their tank.

It is important to understand that Oscars are not aggressive fish, though most hobbyists refer to them as aggressive. Yes, they will defend their territories and chase after problematic tank mates, but they won’t attack other fish without a reason. Instead, they are labeled as being aggressive due to their appetite which makes them eat almost everything in sight.

Oscars are slow-moving fish. They will usually be seen floating in the water column, occasionally moving around to search for food. That being said, they enjoy having plenty of swimming room for when they get quick bursts of energy.

At the same time, these fish can be quite temperamental. If something is added to the tank that they don’t like, they will become less active and might even try to uproot whatever the new addition is. Even then, they are likely to uproot decorations with no intent.

Lastly, oscar fish love their owners. They will recognize the person that feeds them and may eat directly out of their hand.

Tank Mates

Due to tank size and waste management, most hobbyists don’t keep their oscars with other fish, especially not in a community tank. If space isn’t a problem, then there are a few tank mate options that can go with most types of oscar fish.

The goal is to get a fish that is too large to be eaten. Some hobbyist feel getting small, fast, schooling fish that can escape your oscar in a large tank are worth it. The logic here is that they can be easily replaced. Going with small fast fish is an approach I wouldn’t recommend.

One of the best oscar fish pairings is with the severum cichlid (Heros severus). This is because these fish share similar tank and water conditions. Severums are also big enough to hold their own against a full-grown oscar.

Other possible oscar tank mates include:

• Chocolate/emerald cichlids (Hypselecara temporalis)
• True parrot cichlids (Hoplarchus psittacus)
• Green terror cichlids (Andinoacara rivulatus)
• Flagtail prochilodus (Semaprochilodus insignis)
• Silver dollars (Metynnis spp.)

Diet

Oscars may be the least picky of all eaters; oscar fish eat anything that fits inside their mouths, and we mean anything.

Oscar fish are primarily carnivores, meaning they prefer a diet that consists of meaty foods. From there, the possibilities are nearly endless for food options.

These beautiful fish will enjoy a variety of live, frozen, and freeze-dried foods such as:

• Worms (bloodworms, ,blackworms, earthworms, Tubifex worms)
• Shrimp (full raw shrimp, brine shrimp)
• Mollusks (clams, scallops, mussels)
• Insects (insect larvae, crickets, mealworms)

To help keep costs down, oscar fish may be given high-quality cichlid flakes or pellets; pellets may be preferred as some oscars may refuse to come to the surface to eat. Most local pet stores also carry specific oscar fish food.

These large fish will eat as much food as they’re given, which can lead to water quality issues and a lazy fish if overindulged. Eventually, your fish will greet you at the top of the tank waiting to be fed.

Top 8 Types to Choose From

The most common oscar variety to see is the tiger oscar fish. But did you know there are several other types of oscar fish with incredible colors and patterns?

Some of these include the blue oscar fish, black oscar fish, and veil tail oscar fish. Some of these varieties may be harder to find than others, though they all generally share the same care requirements.

1. Tiger

• Adult Size: 1 foot
• Color Pattern: Orange/red marble on black/brown body
• Unique Traits: Dorsal fin eyespot

The tiger oscar fish, also known as the marble cichlid or the velvet cichlid, is the original variation of Astronotus ocellatus. These fish are very common to find in aquarium stores and can be identified by their red and orange marble patterning on their dark body; they will also have a bright, unique eyespot beneath the dorsal fin near the tail.

There is no difference between male and female oscars at any time besides breeding periods. They can successfully be kept in pairs in the aquarium as long as the tank size is adequate.

2. Albino

• Adult Size: 1 foot
• Color Pattern: Light pink shading on platinum white body
• Unique Traits: Pink/red eyes

Albino oscars are a natural albino variety of the tiger oscar fish, Astronotus ocellatus. As an albino fish, these oscars have a genetic disorder that causes reduced production of melanin. This results in a platinum white fish with possible lighter pink shading and no marbling.

However, there are not many true albino oscar fish available; albinism is relatively rare and these fish are in high demand. Because of this, many oscars that are sold as albino are actually lutino.

At first glance, a lutino oscar fish will look albino. The main difference is that lutino oscar fish have marbled, orange patterning while albino oscar fish can have red or pink shading. When in doubt, check the eye color to distinguish between these two very similar-looking fish!

3. Blue

• Adult Size: 1 foot
• Color Pattern: Contrasting shades of blue with some orange marble patterning
• Unique Traits: Intensity of blue varies between individuals

The blue oscar fish (picture source) is extremely rare to find in the aquarium hobby. This is a selectively bred fish that isn’t widely available, leaving it to be on display in only the best of the best aquariums.

These fish have beautiful, intricate shading where some scales are darker and more intense blue than others. This, paired with the contrast created by the orange marbling, can create a dazzling display unlike any other fish.

While blue oscar fish have been compared to other intensely colored cichlids, like the electric blue acara (Andinoacara pulcher), there is a depth that has yet to be recreated in another species.

4. Black

• Adult Size: 1 foot
• Color Pattern: Dark body with shaded bands
• Unique Traits: Light colored belly

Instead of going vibrant, breeders chose to bring out the best of the dark aspects that oscar fish have to offer. The tiger oscar is a naturally dark fish, but hobbyists took it one step further with the black oscar (video source).

The black oscar fish is largely a selectively bred fish that has been designed to bring out the intensity of the browns, blacks, and greys that these fish have to offer. As a result, the bodies of these oscar fish are a uniform shade of grey with overlaying darker, marbled bands. The stomach is usually lighter and some orange or red patterning may also be present.

It should be noted that some tiger oscar fish are naturally darker than others. A black oscar fish will generally lack the intense marbling that comes with the original variation of this fish.

5. Veil Tail

• Adult Size: 1 foot
• Color Pattern: Orange/red marble on black/brown body (tiger oscar variation)
• Unique Traits: Elongated fins

The veil tail oscar fish (video source) is a very beautified fish. These fish have been bred to express extra-long finnage, much like veil tail betta fish. These extended tails are almost threadlike and carry the signature black and orange color combination from regular tiger Oscars.

Though veil tail oscar fish have regular coloration, their patterns have also been exaggerated. Oranges have been intensified and might appear as more organized lines than random blotches across the side of the fish.

It should be noted that these fins are especially susceptible to being nibbled on by other fish in the tank. Extra-long fins may also become too heavy for your oscar fish to carry, leading them to regularly rest on the substrate and other surfaces around the aquarium.

6. Red

• Adult Size: 1 foot
• Color Pattern: Orange/red body with minimal blacks/greys
• Unique Traits: Fiery red body

The red oscar (video source) is the exact opposite of the black oscar. Instead of the dark colors of the tiger oscar being enhanced, the reds and oranges have been maxed out.

Red oscar fish have almost entirely red-orange bodies; there are no remnants of the regular marbled patterning and the majority of the fish is a fiery color. The only parts that usually remain black or grey are the face and fins.

In general, an oscar fish with a higher degree of red is more desirable than one with less. This is one of the most attainable varieties of oscar fish in the hobby, though quality will vary along with the price.

There are many other types of red oscar, including the chili red oscar fish and albino super red tiger oscar fish. These types will vary in intensity and presence of red; some of the highest quality red varieties will present as a uniform red body.

7. Lemon

• Adult Size: 1 foot
• Color Pattern: Light yellow on creamy white body
• Unique Traits: Yellow coloration

Named for obvious reasons, the lemon oscar fish (video source) can be a bright yellow color! However, most lemon oscars are actually creamy white with some hints of yellow; only the highest quality lemon oscars will be bright yellow. Although this coloring might seem difficult to achieve, their popularity has made them largely available.

Yellow is not a very common color to see in predatory freshwater fish, so a lemon oscar fish can instantly become the center of attention for any display. It can also be easy to confuse the lemon oscar with albino or lutino varieties if yellow coloration is minimal.

8. Lutino

• Adult Size: 1 foot
• Color Pattern: Light orange marbling on platinum white body
• Unique Traits: Orange eyes

Often confused with the albino oscar fish, lutino oscars are not truly albino. Instead, these aquarium fish have a near platinum white body with orange or yellow marbled patterning. This is in contrast to true albino oscar fish that lack patterning entirely.

Another main difference between the albino and lutino oscar fish is eye color. Lutino oscars will have orange or dark red eyes while albino fish will have very light pink eyes. Unfortunately, lutino oscars are often sold as albino fish, which can make identification difficult.

How Many Types Are There?

Thanks to the aquarium hobby, there are many different types of oscar fish readily available to most enthusiasts. Scientifically, there are only two species within the Astronotus genus, including Astronotus ocellatus.

Oscars come in a large selection of colors though there is definitely room to expand. Because they require so much space to breed, their true potential remains to be seen.

Final Thoughts

Oscar fish are very hardy fish. Unfortunately, their massive size and tank mate limitations are often unknown to beginner hobbyists looking to purchase a small fish.

Given the right tank size though, there are several types of oscar fish to choose from, all with very similar care requirements but with very different appearances!

📘 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.

Swordtails are one of my go-to recommendations for beginner freshwater tanks — they’re hardy, colorful, and the males have that unmistakable sword tail that makes them stand out. I’ve kept them in community setups for years and they’re genuinely low-maintenance when conditions are right. One thing most guides don’t mention: swordtails and platies can hybridize, which means you sometimes end up with unexpected colors and body shapes in the tank. Here’s everything you need to know about keeping them successfully.

Swordtails are one of the classic beginner livebearers — hardy, colorful, and genuinely interesting to watch. The males develop that distinctive elongated lower tail fin that gives the fish its name, and it’s one of those features that looks better in person than in photos. Like platies and guppies, they’re undemanding and adapt well to a range of conditions, which makes them great for community setups. One thing worth knowing: swordtails and platies are closely related and can actually interbreed, so if you keep both you may end up with hybrids. Males can also be aggressive toward each other, so a ratio of one male to two or three females keeps the peace. Here’s everything you need to keep them well.

A Brief Overview Of The Swordtail Fish

Swordtail Fish Origins and Habitat

Swordtails are one of the most easily recognizable freshwater fish in the entire aquarium hobby. The swordtail fish have been bred to display all colors and pattern variations while still maintaining their status as being one of the easiest species to keep in the freshwater aquarium. These aquarium fish didn’t start out like this, though.

Instead, swordtails originate from North and Central America, specifically from Veracruz in Mexico to northwestern Honduras. There, they are found in a variety of ecosystems with varying altitudes, turbidities, depths, water flows, and even salinities. Most often, they are found in relatively shallow systems with dense vegetation. Adults are likely to be in areas of high flow while juveniles will stick towards the margins where conditions are calmer.

Unfortunately, swordtail fish have entered the waterways of many nonnative continents and countries. They are largely found throughout portions of South America, Africa, and Australia where their invasive populations harm native species¹. Most of these populations have been established through aquarium releases.

Originally, these freshwater species were known as green swordtail fish due to their natural green bodies and red accents. Through the years, these swordtail fish were very carefully bred for color and pattern combinations which eventually led to the overwhelming array of choices available today.

As we’ll see though, colors aren’t the only thing that has changed about the swordtail fish.

For some hobbyists, this can be a problem.

Swordtails, like other livebearing species, are prolific breeders. Anytime there is a male and female swordtail fish present in the tank, there are likely to be baby swordtails. Adding a swordtail to an aquarium can potentially limit hobbyists in their future livestock additions due to reproduction rates and overstocking.

What Do They Look Like?

Swordtails are very recognizable due to their famous feature: their tail that resembles a sword!

On average, swordtail fish grow to be about 5 inches, though they can measure up to 6 inches and can become quite plump. They have a wide, torpedo-shaped body and round stomach. They are unique in that their dorsal fin is higher than other tropical freshwater fish and the bottom ray of their caudal fin extends well past the rest of their tail.

This extension makes sexing swordtail fish easy. Males have this feature while females do not; females have a rounded caudal fin with no other special markings and resemble a platyfish (Xiphophorus maculatus). Males are also typically more colorful and smaller than their female counterparts.

The most common color for swordtails to come in is red; the whole body will be red with a noticeable darker mid-lateral line, especially on the males. The fin extension may also be a different color from the rest of the body or have different colored margins depending on the variety of fish.

Swordtail Varieties

Once originally known as the green swordtail, beautiful though plain in color, these aquarium fish have been selectively bred to display almost every color and every pattern combination, mostly consisting of reds, yellows, and oranges.

It should be noted that swordtails have successfully been hybridized with other species within the Xiphophorus genus, making the possibilities endless.

Here are some of the most common colors to come across as well as the most designer swordtail varieties available:

Red swordtail. The red swordtail fish is the most common variation to come across. Both males and females are uniform in color, though males may have a black margin to their tail fin extension.

Red wag swordtail. The red wag swordtail is a normal swordtail but with black fins. All other features and requirements are the same as the regular red swordtail.

Pineapple swordtail. The swordtail fish with the best name, these swordtails have a red back with a pale yellow body and white belly. They may have slightly shorter fin extensions than other varieties, which can be a favorable combination along with their colors.

Red lyretail swordtail. These swordtail fish are named after the instrument as both males and females have a u-shaped tail fin. The body is light orange/red while the dorsal and tail fins are usually black.

Hi fin lyretail swordtail. An even more accentuated version of the red lyretail swordtail, the hi fin attribute comes from the extremely elongated dorsal fin which is almost as long as their tails; females do not have such exaggerated features. Colors include red, orange, and yellow. Because of their extreme features, hi fin lyretail swordtails need at least a 30-gallon tank and very carefully chosen tank mates that won’t nip at fins.

Are They A Type Of Molly Fish?

Mollies, platies, swordtails. They all kind of look the same and have similar care requirements, but what makes them different?

Swordtails are not a type of molly or platy, even though they are all closely related. Looking at the scientific categorization of these freshwater species, swordtails are Xiphophorus hellerii, mollies are Poecilia latipinna, and platies are Xiphophorus maculatus.

As we can see, mollies are in a different scientific genus altogether. However, swordtails are in the same genus, Xiphophorus, as platies and are very closely related. Though there are slight variations between these two species–namely, the absence of the elongated tail fin in platies–there is a larger difference in geographic distribution.

The Xiphophorus genus is split into three phylogeographic clades based on origin. Platies are native to eastern Mexico and Central America. Northern swordtails are found in very specific regions of northeastern Mexico. Southern swordtails, like the ones listed in this article, originate from southern Mexico and northern Central America.

Care – Temperament and Activity Level

Swordtail fish are a favorite among beginner hobbyists due to their flashy and active behavior. These fish will quickly fill up empty space in the upper and middle portions of the tank, only venturing to the bottom for food.

While great additions to the community tank, swordtails can be slightly aggressive towards each other, specifically from male to male. As we’ll see, it’s recommended to keep a very high male-to-female ratio to keep males from becoming aggressive to one another. Males may also become aggressive to similar-looking fish of other species.

Otherwise, these active fish will provide constant movement to the aquarium display. When they’re not looking for food to pick off of plants and decorations, they’ll be looking to mate.

What Are Good Tank Mates for Swordtails?

Swordtails are compatible with most freshwater fish. They are big enough to tolerate larger, slightly more aggressive species while bringing out the best in smaller, schooling types.

The most important thing to consider when choosing swordtail fish tank mates is fin nipping. These fish have beautiful fins that you don’t want to see get shredded or infected with fin rot!

Here are some of the best tank mates for swordtails:

• Platies
• Mollies
• Guppies
• Corydoras
• Angelfish
• Gouramis
• Tetras
• Danios
• Barbs

Remember that swordtail fish are capable of hybridizing with platies. While this isn’t necessarily wrong to allow happen, hybridization can lead to some genetic mutations and loss of color lineages.

It should also be noted that keeping swordtails with other prolific livebearers, like platies or guppies, can quickly lead to overpopulation if not controlled.

How Many Swordtails Should Be Kept Together?

Contrary to popular belief, swordtail fish are not a schooling species. They like to be in group settings but won’t actively follow around the other swordtails in the tank for protection.

That being said, swordtail fish do best when kept in groups of 4 to 6. At least two or three females should be kept for every one male. Hobbyists have had success keeping only one male swordtail fish in a tank–which is the preferred setting if wanting to avoid any chances of reproduction–but they will thrive in a social community setting.

Since male and female fish are so easy to tell apart, it is recommended to skip a male addition altogether. However, keep in mind that there is the chance for females to already be pregnant before adding them to your tank.

Can Bettas and Swordtails Live Together?

Another great beginner fish is the Betta (Betta splendens). These fish are nowhere near as active as the swordtail fish but males are especially colorful with bold personalities. So much so that betta fish are notorious fighting fish that could easily injure a swordtail if paired together.

Because of this, bettas should not be attempted to live with swordtails. These two fish are not compatible tank mates as swordtails are overly active and can become fin nippers. This could stress out your betta and lead to infection.

What Do They Eat?

Swordtail fish are omnivores and will gladly eat whatever they are given. They will love foraging for food on live plants and other decorations, but will readily accept an assortment of live, frozen, and freeze-dried foods, like bloodworms, brine shrimp, and mosquito larvae.

To maintain their color, a high-quality tropical fish flake food or pellet should be offered daily; quality flake food is slightly more preferred as they stay at the water’s surface longer. Swordtail fish may also be given algae pellets or flakes as well as blanched vegetables from time to time.

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What Plants Do They Eat?

While foraging for food on live plants, swordtail fish have been known to accidentally–or purposely–eat some leaves.

Swordtails are great algae eaters and will help keep plants free from pests. However, they are so efficient that they might not be able to tell algae apart from a desired live plant. This behavior can be deterred by feeding more often or adding less desired plants that are meant to be eaten.

Setting Up Your Tank

Swordtails are very hardy fish and can live in a variety of aquarium setups. Like any fish, swordtail fish need to be kept in a fully cycled aquarium with stable water parameters. Swordtail fish can be slightly messier than other freshwater fish so it’s important that the mechanical and biological filtration systems are ready to handle the bioload.

Swordtail fish look especially great in a densely planted aquarium on a dark substrate. They will need an aquarium hood to prevent them from jumping out.

Tank Size

Swordtail fish are one of the more demanding beginner species when it comes to tank size. These fish are relatively big, active, and need to be kept in small groups. They can also create a lot of bioload for so few fish.

To help bolster the biological filtration system and to give your swordtail fish enough space to swim, a 20 gallon long tank is recommended. A long tank will give much more space for your fish to swim than a tall tank. Even bigger tanks will allow for a much larger selection of fish to choose from.

Filtration

To keep up with bioload, the filter should be rated for at least 2x the size of the aquarium. In regards to swordtail fish, it’s pretty difficult to give too much filtration.

If you remember, these fish live in areas of high flow in their natural habitat. Though most swordtails in the aquarium hobby have adapted to living in community tanks with minimal flow, swordtail fish can surely survive a tank set up with a high water current.

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This water flow can be created with filters, powerheads, and wavemakers. Just remember that other community fish might not be able to handle such high water currents as well as your swordtail fish.

Water Parameters

Swordtail fish are very forgiving of incorrect water parameters, but that doesn’t mean that you shouldn’t strive to give them the best. Like any other fish, swordtails will succumb to sudden fluctuations in water parameters.

Swordtails can be kept in a cooler water temperature, though stability is key. A changing water temperature can quickly cause fish to go into shock, so a heater for temperature regulation is strongly recommended. It is also advised to keep swordtail fish in tropical water temperatures in order to have the most choices when it comes to possible tank mates.

Otherwise, swordtail fish need a neutral pH level with limited nitrates.

Breeding

Breeding swordtail fish is straightforward and usually a matter of when rather than if. Swordtails are livebearing fish which means that they will give birth to live young.

First, get a good mix of female and male swordtails. Some hobbyists choose to remove their mating pairs from the main tank display into a specific breeding tank, though this isn’t entirely necessary.

Once ready, males will chase after females and the two fish will mate. Over the next few weeks, the female will grow plumper in appearance until she’s ready to give birth. When she’s ready, she will birth anywhere from 50-200 live fry. Not to mention that females can give birth once every month or so!

The fry will be immediately independent and susceptible to being eaten by the parents and other fish; this usually isn’t a concern as the brood is so large and reproduction can happen so often.

To increase the chances of fry surviving, they should be placed in their own tank or given plenty of coverage in the form of live plants. Small foods, like baby brine shrimp, will need to be offered until they are ready to accept larger foods.

Final Thoughts

Swordtail fish are a popular addition to beginner hobbyist’s fish tanks. These swordtail fish are big, active, and easy to care for but do require some special attention when it comes to water flow and keeping males together.

Otherwise, these peaceful fish are fun and easy to breed, allowing hobbyists to make their own designer swordtail varieties along the way!

📘 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.

Blue freshwater fish are genuinely hard to find — and I say that as someone who’s been searching for them for 25+ years. True blue coloration in freshwater is rare compared to saltwater, so when I see a fish that genuinely delivers on it, I take notice. These are my top picks after years of keeping and observing them in my own tanks, ranked by how reliably they display that blue color in home aquarium conditions.

Blue is genuinely one of the harder colors to find in freshwater fish — it’s more common in saltwater, which is part of what makes a well-chosen blue freshwater species stand out in a tank. After 25 years in both freshwater and reef keeping, I’ve learned that “blue” can mean a lot of things depending on the fish, the lighting, and even the mood of the animal. Some blues are electric and vivid; others are subtle and iridescent. This list covers 15 of the best options across different tank sizes and care levels, so there’s something here whether you’re running a community tank or a species-only setup.

15 Best Blue Freshwater Fish Species

Choosing the right aquarium fish involves some careful thought. It’s really important to know how big they grow, how much space they need, and whether they will be happy in the kind of water you have.

To make choosing the perfect bluefish easier, I’ve included the following important stats for each species:

• Scientific Name
• Difficulty Level
• Adult Size
• Temperament
• Origin
• Minimum Tank Size
• Temperature
• Diet
• pH
• Difficulty to breed
• Planted tank suitability

Now you’re ready to meet some awesome bluefish! Check out our video above from our YouTube Channel. We go over more details in the blog post below. If you like our content, be sure to subscribe. We post new videos every week!

1. Betta fish/ Siamese fighting fish

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Betta Fish are one of the most beautiful varieties of freshwater fish available in the hobby. Easy to care for with plenty of varieties!

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• Scientific Name: Betta splendens
• Difficulty Level: Moderate
• Adult Size: 2.5 inches
• Minimum Tank Size: 5 gallons
• Temperature: 75-82°F
• pH: 6.5-7.5
• Temperament: Aggressive
• Origin: Southeast Asia
• Diet: Carnivore
• Difficulty to breed: Moderate
• Planted tank suitability: Yes

Betta fish are one of the best blue fish for fishkeepers who want to keep a nano aquarium. Of course, not all bettas are blue, so you’ll need to shop around for a specimen that suits your taste. These pretty fish come in a huge variety of different fin shapes, and can be found in solid blue, or combinations of colors that include everything from turquoise to deep blue!

It’s usually best to keep betta fish on their own. Male bettas are very aggressive fish and will fight and kill other male bettas. Female bettas are less aggressive than males but it can still be risky to keep more than one in the same aquarium.

You can keep a betta fish with tank mates in larger tanks. You just have to be careful about what you add as the betta can prey on small inverts and will be nipped by overactive fish.

2. Fancy Guppies

Guppy Fish

An undemanding fish that is a livebearer. Many varieties available

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• Scientific Name: Poecilia reticulata
• Difficulty Level: Easy
• Adult Size: 1.5-2.5 inches
• Minimum Tank Size: 10 gallons
• Temperature: 64-82°F
• pH: 7-8.5
• Temperament: Peaceful
• Origin: Northeastern South America
• Diet: Omnivorous
• Difficulty to breed: Easy
• Planted tank suitability: Yes

Guppies are another hugely popular aquarium fish that come in a range of patterns and colors-including blue! These aquarium fish come in many different shades of blue, including sky and royal blue.

Guppies are peaceful community fish that get along great with other fish. The fancy guppy is a very hardy fish that is easy to care for and will thrive in just about any freshwater tank setup with hard water.

3. Blue Gourami

• Scientific Name: Trichopodus trichopterus
• Difficulty Level: Easy
• Adult Size: 5 inches
• Minimum Tank Size: 20 gallons
• Temperature: 75-86°F
• pH: 5.5-8.5
• Temperament: Semi-aggressive
• Origin: Southeast Asia
• Diet: Omnivorous
• Difficulty to breed: Moderate
• Planted tank suitability: Yes

The blue gourami is also known as the three spot gourami. This hardy and easy to care for species is great for fishkeepers who want medium-sized blue aquarium fish.

This gourami species comes in a few different breeds, and not all of them are blue. The best options are the wild 3 spotted form, or even better, the opaline form if you want a really great centerpiece fish.

4. German Blue Rams

• Scientific Name: Mikrogeophagus ramirezi
• Difficulty Level: Moderate/advanced
• Adult Size: 1.5 inches
• Minimum Tank Size: 15 gallons
• Temperature: 80-86°F
• pH: 4-7
• Temperament: Peaceful
• Origin: Venezuela, Colombia
• Diet: Omnivorous
• Difficulty to breed: Moderate
• Planted tank suitability: Yes

The German blue ram is one of my favorite blue fish species. If you’re looking for amazing color, the ‘electric blue’ breed will really impress you!

These gorgeous little cichlids are super peaceful fish and stay very small, unlike most other South American cichlids. Unfortunately, the German blue ram is not great for beginners because they need perfect water quality to stay healthy.

5. Blue Peacock Cichlid

• Scientific Name: Aulonocara nyassae
• Difficulty Level: Moderate
• Adult Size: 7 inches
• Minimum Tank Size: 55 gallons
• Temperature: 76-82°F
• pH: 7.8-8.6
• Temperament: Semi-aggressive
• Origin: Lake Malawi, Africa
• Diet: Carnivorous
• Difficulty to breed: Moderate
• Planted tank suitability: Yes

The blue peacock cichlid is an awesome blue fish from Lake Malawi in Africa. Like most other African cichlids, these fish need high pH water to thrive. These fish are classified as semi-aggressive and become pretty aggressive when breeding, a time when they are their most colorful!

It is best to keep the blue peacock cichlid fish in a group of 1 male and 3 or 4 females to prevent fighting. They are not your typical community fish, and the best tank mates for these fish are other peacock cichlids.

6. Blue Zebra Cichlid

• Scientific Name: Maylandia callainos/ Metriaclima callainos
• Difficulty Level: Moderate
• Adult Size: 6 inches
• Minimum Tank Size: 50 gallons
• Temperature: 76-82°F
• pH: 7.8-8.6
• Temperament: Semi-aggressive
• Origin: Lake Malawi, Africa
• Diet: Herbivore
• Difficulty to breed: Moderate
• Planted tank suitability: Possible

The cobalt blue zebra cichlid is an mbuna cichlid. These fish are known for being quite aggressive if not kept with the right tankmates. It is best to keep one male with 3 or 4 females to limit aggression.

These fish are not suitable for most community aquariums, but they can be amazing in mbuna aquariums with other species of African cichlids.

7. Electric Blue Johanni

• Scientific Name: Melanochromis johannii
• Difficulty Level: Moderate
• Adult Size: 4-5 inches
• Minimum Tank Size: 40 gallons
• Temperature: 73-81°F
• pH: 7.6-8.8
• Temperament: Semi-aggressive
• Origin: Lake Malawi, Africa
• Diet: Omnivore
• Difficulty to breed: Moderate
• Planted tank suitability: Possible

The electric blue johanni is a great little African cichlid with vibrant blue colors. It is only the males that are dark blue, however, and the females are a beautiful golden orange color. Some of the best tank mates for mbuna cichlids like electric blue johannis are other mbuna cichlids from lake Malawi.

8. Frontosa

• Scientific Name: Cyphotilapia frontosa
• Difficulty Level: Moderate
• Adult Size: 10-12 inches
• Minimum Tank Size: 75 gallons
• Temperature: 72-82°F
• pH: 8-9
• Temperament: Semi-aggressive
• Origin: Lake Tanganyika, Africa
• Diet: Carnivore
• Difficulty to breed: Moderate
• Planted tank suitability: Possible

The frontosa, or humphead cichlid, is a great species for fish keepers who want a large and dramatic display tank! These fish are not pure blue, but rather silvery blue with bold vertical black bars. Although you could keep a frontosa cichlid in a tank as small as 70 gallons, you’ll really want a 180-gallon tank or larger to keep them in a group.

9. Discus Fish

• Scientific Name: Symphysodon aequifasciata
• Difficulty Level: Moderate
• Adult Size: 8 inches
• Minimum Tank Size: 55 gallons
• Temperature: 79-86°F
• pH: 6.1-7.5
• Temperament: Peaceful
• Origin: Brazil
• Diet: Omnivorous
• Difficulty to breed: Moderate
• Planted tank suitability: Yes

Discus fish are one of the most beautiful (and peaceful) cichlids in the hobby. These colorful freshwater fish get their name for their round, disc-shaped bodies.

There are many varieties of discus available, including some amazing blue types like the cobalt, blue snakeskin, and blue diamond discus.

10. Cardinal Tetra

Cardinal Tetra

A very popular schooling fish. Looks like the Neon Tetra, but with longer blue and red stripes. Grows larger than a neon tetra as well

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• Scientific Name: Paracheirodon axelrodi
• Difficulty Level: Moderate
• Adult Size: 1.5 inches
• Minimum Tank Size: 15 gallons
• Temperature: 73-81°F
• pH: 5.5-7.5
• Temperament: Peaceful
• Origin: Brazil and Venezuela
• Diet: Omnivorous
• Difficulty to breed: Moderate
• Planted tank suitability: Yes

Cardinal tetras are gorgeous fish that have vivid blue stripes that run the length of their bodies from their bright blue eyes almost to the start of their caudal fin. Cardinal tetras look very similar to our next species, the neon tetra, but have more contrast between red and blue.

These peaceful community fish get along great with other smaller fish. They are ideal for a community setup, especially if kept in schools of 8 or more.

11. Neon Tetra

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

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• Scientific Name: Paracheirodon innesi
• Difficulty Level: Easy
• Adult Size: 1.25 inch
• Minimum Tank Size: 15 gallons
• Temperature: 70-77°F
• pH: 5-7
• Temperament: Peaceful
• Origin: Brazil, Colombia, Peru
• Diet: Omnivorous
• Difficulty to breed: Moderate
• Planted tank suitability: Yes

Neon tetras are amazing blue schooling fish with bright blue stripes along their sides. These colorful freshwater fish are similar to cardinal tetras but slightly smaller and do not have as much red color.

Neon tetras are very peaceful fish that get along great with other peaceful tank mates. Like other tetras, these fish should be kept in groups of 8 or more to see them school and behave confidently.

12. Blue Glofish

• Scientific Name: Various
• Difficulty Level: Easy-moderate
• Adult Size: 2 inches for danios and tetras, 6 inches for sharks
• Minimum Tank Size: 15 gallons for danios and tetras, 55 gallons for sharks
• Temperature: 70-75°F
• pH: 7-8
• Temperament: Peaceful/ semi-aggressive
• Origin: Tank bred
• Diet: Omnivorous
• Difficulty to breed: Moderate
• Planted tank suitability: Yes

Glofish are some of the most colorful freshwater fish in the aquarium hobby. These fish are genetically modified to show the most amazing vivid color. The cosmic blue tetras, (also available in the longfin variety), cosmic blue danios, and cosmic blue sharks are awesome blue fish for freshwater aquariums.

The tetras and danios are very peaceful schooling fish for an awesome freshwater community tank. They grow to just 2 inches or so in length and should be kept in schools of 6 or more. The cosmic blue sharks are larger fish that are classified as semi-aggressive.

13. Praecox Rainbowfish (Dwarf Neon Rainbowfish)

Dwarf Neon Rainbowfish

A colorful rainbowfish that only grows up to 3 inches in length. Best in groups of 8 to 10

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• Scientific Name: Melanotaenia praecox
• Difficulty Level: Easy
• Adult Size: 3 inches
• Minimum Tank Size: 15 gallons
• Temperature: 73-82°F
• pH: 6.8-7.5
• Temperament: Peaceful
• Origin: Indonesia
• Diet: Omnivorous
• Difficulty to breed: Moderate
• Planted tank suitability: Yes

The praecox rainbowfish is a beautiful blue fish with red fins and a red tail. This colorful fish is also known as the dwarf neon rainbowfish because it maxes out at just 3 inches or so and glows with color in the right lighting.

Praecox rainbowfish are active fish that do great in an aquarium community with other shoaling fish. They are great-looking fish to add as a school in medium to large-sized aquariums.

14. Electric Blue Crayfish

• Scientific Name: Procambarus alleni
• Difficulty Level: Easy
• Adult Size: 4-6 inches
• Minimum Tank Size: 30 gallons
• Temperature: 65-70°F
• pH: 6.5-7.5
• Temperament: Semi-aggressive
• Origin: Southeastern United States
• Diet: Omnivorous
• Difficulty to breed: Moderate
• Planted tank suitability: No

If you’re looking for something a little different for your blue fish aquarium, look no further than the electric blue crayfish (video source)! These awesome critters are native to the United States and they thrive in fish tanks.

Electric blue crayfish are opportunistic feeders that do occasionally catch slow-moving fish. They also love to eat aquarium plants, so they are not ideal for planted tanks. Fast tankmates are recommended, thought not guaranteed that they will not eaten.

15. Freshwater Shrimp

Freshwater Shrimp

Freshwater aquarium shrimp are a great addition to small tanks and aquascapes. Peaceful, full of personality, and colorful. Many varieties are available.

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• Scientific Name: Neocaridina davidi, Caridina cantonensis, Caridina serrata
• Difficulty Level: Easy/moderate
• Adult Size: 0.75-1.5 inches
• Minimum Tank Size: 5 gallons
• Temperature: 72-82°F
• pH: 7-8
• Temperament: Peaceful
• Origin: Southeast Asia
• Diet: Omnivorous
• Difficulty to breed: Easy
• Planted tank suitability: Yes

There are many amazing blue shrimps available in the aquarium hobby. Some great examples include the blue velvet shrimp/ blue dream shrimp (Neocaridina davidi), the blue bolt shrimp (Caridina cantonensis), and the aura blue shrimp (Caridina serrata).

Adult shrimp can be kept with some small community fish, but larger fish will probably see your shrimp as a tasty snack! the great thing about shrimp is that you can keep them in a tank of just 5 gallons or so, making them a perfect choice when you don’t have a lot of room.

Bonus for Freshwater Aquariums

Just in case you’re curious about even more blue fish for freshwater aquariums, here are a few more beautiful fish species to check out!

• Electric blue acara
• Electric blue hap cichlid
• Jewel cichlid
• Blue Jack Dempsey fish
• Green terror cichlids
• Powder blue gourami/ blue dwarf gourami
• Paradise fish

Aquarium Fish Care – The Basics

If you’re new to fish keeping, there are some very important things to know before bringing your new blue fish home. Different fish species have different care needs, but the following tips are a good starting point.

Tank Setup

Setting up a great tank is the first step, and this should always be done before you bring your fish home! In fact, you should set up your tank at least a few weeks before introducing any fish to get it fully cycled and ready.

Read on for a basic list of what you’ll need!

Essential equipment

The most important items you’ll need to set up a great freshwater aquarium for blue fish are:

• Fish tank with a hood/cover- Match the size of the tank to the minimum tank size of the fish you want to keep. Bigger is always better, so go a little larger if you can.
• Filter- A filter is extremely important for keeping your water clean and healthy. Choose a filter that is rated for your tank size or larger.
• Aquarium light- Good lighting will make your fish look really amazing. Set your lights on a timer so that they fire up and switch off at the same time every day. This will give your pets a natural day/night rhythm.
• Heater- Tropical fish need a heater to keep the water temperature stable in their preferred range. Choose a model that matches your tank size.
• Thermometer

These are the basic components of a tropical fish tank. While it is possible to set up a fish tank with just these components, you’ll also want to decorate your tank. Read on to learn more.

Decor

You can get creative or aim to make a really natural-looking environment for your fish. The choice is yours! Whatever you choose to decorate your tank with, however, always make sure it is fish-safe.

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Pick up a selection of the following items to make a great home for your blue fish:

• Substrate (gravel/sand)
• Hardscape (Driftwood, lava rocks, etc.)
• Decorations and ornaments

Feeding your fish

Different species of fish have different diets, so make sure to research the needs of your blue fish before picking up some food. Read on to learn some popular aquarium fish food types and how to feed your fish!

Food types

Most popular aquarium fish can be fed a regular diet of prepared dried foods. These come in different shapes and sizes and are designed for different types of fish. Prepared foods can either float or sink.

Here are some common examples of prepared foods:

• Fish flakes
• Pellets
• Granules
• Wafers
• Frozen food

Best Tropical Fish Flake Food

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Apart from their regular daily food source, omnivorous and carnivorous fish will benefit hugely from the occasional meal of live or frozen food. These should not be provided every day, but rather as a supplement to improve color and condition. The best choices are:

• Frozen brine shrimp
• Bloodworms
• Blackworms

How much to feed your fish

Overfeeding is very bad for the health of your fish and can lead to poor water quality as uneaten food spoils in the water. Most aquarium fish can be fed once or twice a day when the lights are on. Provide only as much food as the fish can finish in a minute or two.

Maintenance

Keeping your fish tank looking amazing requires you to do some regular aquarium maintenance. You’ll need to clean your aquarium glass with an algae scraper when necessary, and you’ll also need to rinse out your filter if it becomes clogged.

The most important side of maintenance is to perform partial water changes once or twice a month. This will prevent the build-up of harmful chemicals in the water.

Testing

You’ll need a test kit to test your aquarium water quality and find out what your water parameters are. Liquid or strip test kits are really easy to use and very affordable. Use your test kit before adding any fish to your tank and then every week to monitor your water quality.

Choose a test kit that can measure the following parameters:

• pH
• Hardness
• Ammonia
• Nitrite
• Nitrate

Where to Buy

Most of the species on this list can be found at your local fish or pet store. If you can’t find what you’re looking for, you can always order from a trusted online retailer and have your new pets delivered to your home!

FAQS

Final Thoughts

There’s something about blue fish that really makes for a great display tank! With all the great species in this list, there’s a species to suit any aquarist. I hope you found some great ideas for your own tank, and remember, have fun!

Do you keep blue fish in your freshwater tank? Tell us about your favorite species 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.