Fish For 55 Gallon Tank – 21 Great Selections (with Photos)

55-gallon aquariums have both pros and cons. On the plus side, this tank size allows you to keep a huge range of different fish species. On the downside, choosing fish from all those options can be quite a challenge!

Four-foot tanks are big enough for many of the hobby’s most popular medium-sized fish yet small enough for keeping schools of nano fish like tetras. They’re also relatively stable and easy to maintain, which is great for beginners or fishkeepers who don’t want to spend too much time on maintenance.

Standard 55-gallon fish tanks even make great saltwater tanks, but that’s a subject for another day. In this guide, I’ll be focusing on 21 freshwater species that are widely available in the fish keeping hobby. Let’s get started!

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

• 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.

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

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• 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

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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
• 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

• 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

• 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.

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.

FAQs

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!

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Mark Valderrama

I’m thrilled that you found Aquarium Store Depot! Here you’ll find information on fish, aquariums, and all things aquatics related. I’m a hobbyist (being doing this since I was 11) and here to help other hobbyists thrive with their aquariums! I adhere to a high quality Editorial Process and Review products with real life field usage and practical analysis.

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