What fish can you put in a 55 gallon tank?

A 55 gallon aquarium provides ample space for a variety of freshwater and saltwater fish. The key considerations when stocking a 55 gallon tank are the tank inhabitants’ adult size, behavior, water parameter needs, and bioload. Careful planning is required to create a stable and healthy aquatic environment. This article provides quick answers about suitable fish for a 55 gallon aquarium, followed by in-depth information on recommended tankmates organized by fish type.

Quick Answers

  • Freshwater fish like guppies, platies, mollies, danios, tetras, rasboras, barbs, corydoras and bristlenose plecos are suitable for a 55 gallon tank.
  • Larger freshwater fish that can work in a 55 gallon include angelfish, gouramis, rainbowfish, some cichlids and larger catfish like pictus cats.
  • For saltwater, smaller species of clownfish, gobies, blennies, chromis,Gramma species, damselfish, cardinals, basslets and firefish are appropriate.
  • Some medium saltwater species like clowns, banggai cardinals, watchman gobies, blennies, damsels, dottybacks, hawkfish, wrasse and small angels can be housed.
  • Avoid aggressive fish like oscars, arowana and large plecos that will outgrow a 55 gallon tank.
  • Choose tankmates carefully and do not overstock the aquarium.

Recommended Freshwater Fish for a 55 Gallon Tank

Peaceful Community Fish

Some great options for peaceful community fish in a 55 gallon freshwater aquarium include:

Tetras: Most tetras stay under 2 inches and do well in groups in a larger aquarium. Good choices are neon, cardinal, rummynose, ember, black neon and glowlight tetras. Avoid fin nippers like bue-eyed tetras.

Rasboras: Many rasboras like harlequin, lambchop, glowlight and chili rasboras are perfect for community tanks. They are small, peaceful schooling fish.

Danios: Zebra danios are a hardy and active tiny fish that should be kept in schools. Giant danios grow larger but are peaceful.

Rainbowfish: Boesmani, threadfin and dwarf neon rainbowfish are relatively peaceful medium sized community fish.

Mollies: Sailfin, black, and Dalmatian mollies are livebearers that stay under 3-4 inches. Avoid mixing guppies and mollies though, as they can hybridize.

Platies: Varieties like mickey mouse,tuxedo,sunset and comet platies grow 2-3 inches and do well in community tanks.

Guppies are classic small bright community fish that should be kept in single sex groups unless breeding is desired. Fancy varieties produce vibrant colors.

Swordtails come in attractive varieties. Modest sized peaceful fish around 5 inches. Females tend to be less aggressive.

Hatchetfish are unique surface dwelling fish that stay under 2 inches. A group of 6 or more is recommended.

Pencilfish like neon dwarf pencilfish are shy but colorful schooling fish that stay under 2 inches. A peaceful tank is essential.

Fish Adult Size
Neon Tetra 1.5 inches
Harlequin Rasbora 2 inches
Zebra Danio 2-3 inches
Boesmani Rainbowfish 4-6 inches
Sailfin Molly 3-4 inches
Sunset Platy 2-3 inches
Fancy Guppy 1-2 inches
Swordtail 4-6 inches
Marble Hatchetfish 2 inches
Neon Dwarf Pencilfish 1.5 inches

Centerpiece Fish

Some suitable centerpiece fish for a 55 gallon community tank include:

Gouramis: Pearl and honey gouramis are peaceful medium sized gouramis. Avoid aggressive three spot or giant gouramis.

Discus fish are challenging but make stunning centerpiece fish. Stick to smaller varieties like cobalt or turquoise discus in a 55 gallon. They require warm pristine water.

Angelfish are cichlid family fish that do well with small peaceful tank mates. Their elegant flowing fins add grace to the aquarium.

Dwarf cichlids like German blue rams are good 55 gallon choices. Avoid most African cichlids as they grow large and aggressive.

Giant danios grow to 4-6 inches but are active and peaceful. Their bold stripes stand out in contrast to small colored fish.

Fish Adult Size
Pearl Gourami 4-6 inches
Turquoise Discus 6-8 inches
Veiltail Angelfish 6-8 inches
German Blue Ram 3 inches
Giant Danio 4-6 inches

Bottom Dwellers

Some bottom dwelling fish suitable for a 55 gallon tank include:

Corydoras catfish are best kept in schools. Pygmy corys stay under 2 inches while peppered and albino cory reach 3-4 inches.

Bristlenose plecos only grow to around 5 inches and help clean algae off of surfaces. Avoid common pleco species.

Kuhli loaches are eel like bottom feeders that grow to 4-6 inches. They appreciate having hiding spots and being kept in groups.

Bichirs, like the ornate or albino varieties are other unique bottom dwellers. They can reach 12 inches so space is a consideration.

Synodontis catfish are another option. Some more manageable species are cuckoo, eupterus and nigriventris which stay under 5 inches.

Fish Adult Size
Pygmy Cory 1-2 inches
Bristlenose Pleco 4-6 inches
Kuhli Loach 4-6 inches
Ornate Bichir 8-12 inches
Cuckoo Synodontis 4-5 inches

Saltwater Fish for a 55 Gallon Reef Aquarium

Small Peaceful Fish

There are many options for small peaceful saltwater fish like:

Clownfish are classic reef safe clowns that do well singly or pairs. Percula, ocellaris, and skunk clown species stay under 3 inches.

Blennies like lawnmower, scooter, skunk blennies are bottom dwelling fish that reach 3-5 inches. They have great personality.

Gobies including clown, neon, firefish, watchman fish stay under 3 inches and are great reef tank choices.

Cardinalfish like banggai, pajama, blue-throated cardinals are shy but peaceful fish reaching around 3-4 inches in length.

Basslets (grammas) like royal, blackcap, coral beauty basslets are small and reef compatible. Several species stay under 3 inches.

Damselfish including 3 striped, electric blue, and lemon damsels are hardy small fish but can be territorial. Better in larger groups.

Chromis are schooling fish that do well kept in groups. Blue green, black, and bicolor chromis stay under 4 inches.

Fish Adult Size
Percula Clownfish 3 inches
Skunk Blenny 3-4 inches
Neon Goby 2 inches
Bangai Cardinalfish 3-4 inches
Royal Gramma 3 inches
3 Striped Damselfish 4 inches
Blue Green Chromis 3-4 inches

Medium Reef Fish

Some medium sized reef fish suitable for a 55 gallon include:

Angelfish like the flame angel grow to around 5 inches and need peaceful tank mates. Avoid large angel species.

Butterflyfish – some smaller species like the spotted butterfly work well in larger reef tanks. They grow to around 5 inches.

Wrasse including cleaner, leopard, six-line wrasse are suitable smaller reef wrasses if provided plenty of rock work. They reach 4-6 inches.

Tangs should be chosen carefully based on adult size. Kole and bristletooth tangs stay under 5 inches. Avoid larger tangs.

Pseudochromis such as the firetail dottyback grow to around 3-4 inches but can be aggressive. Best kept singly.

Filefish are oddball fish but some species like the One Spot Foxface are smaller and can work in larger tanks. They reach around 5 inches.

Hawkfish like the flame hawkfish remain a more modest 4-5 inches, but require tanks with tight fitting lids.

Fish Adult Size
Flame Angel 4-5 inches
Spotted Butterflyfish 4-6 inches
Six Line Wrasse 4-6 inches
Kole Tang 4 inches
Firetail Dottyback 3-4 inches
One Spot Foxface 4-6 inches
Flame Hawkfish 4-5 inches

Tank Setup Considerations

To help create a healthy and stable aquarium environment in a 55 gallon tank, keep these tank setup guidelines in mind:

  • Stock the aquarium slowly over time instead of all at once.
  • Choose fish appropriate for the tank size. Avoid fish that grow over 12 inches.
  • Select species that fit the tank inhabitants’ temperament, water parameters and space needs.
  • For schooling fish, purchase groups of at least 6 fish.
  • Include bottom dwellers like plecos and cory cats to help clean up and aerate the substrate.
  • Incorporate enough hiding spots, caves and sight breaks to allow fish to establish territories and reduce aggression.
  • Limit the number of territorial or aggressive fish in the aquarium.
  • Use efficient filtration sized for at least twice the water volume.
  • Perform partial water changes of 25-30% weekly to maintain clean water.
  • Test water parameters regularly and address any issues promptly.
  • Feed a high quality varied diet in moderation.
  • Introduce tankmates carefully and observe their interactions.
  • Have a plan in place to rehome any fish that don’t acclimate or grow too large.


A 55 gallon aquarium provides space to create an impressive freshwater community tank or mini saltwater reef environment. Take time stocking the tank and include fish appropriate for a 55 gallon system. Choose active schooling fish, striking centerpiece fish, and bottom dwelling clean up crews. Supplement with ample hiding spaces, rock work and efficient filtration. Work to maintain excellent water quality and compatibility between tankmates. With good planning and proper fish selection, a 55 gallon tank can produce a diverse, vibrant and healthy aquatic ecosystem.

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