Best fish for a 55 gallon tank
At 122 cm long, a 55 gallon is the first size where active schooling fish such as barbs and danios have real swimming room.
Checked by our tank model as a starter group in an empty, cycled 55G (122 × 33 × 53 cm) with a filter rated for it. One group per tank; mix species with the planner.
Good fits
- Fits
Neon tetra
Paracheirodon innesipH 7.2 works for Neon tetra, but 5.0–7.0 is ideal.
group of 8 · 1.2 in · 17+ gal · 70–77°F · pH 5–7 - Fits
Harlequin rasbora
Trigonostigma heteromorphapH 7.2 works for Harlequin rasbora, but 6.0–7.0 is ideal.
group of 8 · 1.4 in · 17+ gal · 73–81°F · pH 6–7 - Fits
Panda corydoras
Corydoras pandaFriendly armoured catfish that sift the sand in groups; need soft substrate and a group of six or more.
group of 6 · 1.6 in · 17+ gal · 72–77°F · pH 6–7.2 - Fits
Otocinclus
Otocinclus vittatusTiny algae grazers for mature planted tanks; keep six or more and supplement with vegetables.
group of 6 · 1.4 in · 17+ gal · 72–79°F · pH 6–7.2 - Fits
Cherry shrimp
Neocaridina davidiTemperature 76°F works for Cherry shrimp, but 72–75°F is ideal.
group of 10 · 1.6 in · 4+ gal · 72–75°F · pH 6.5–7.8 - Fits
Angelfish
Pterophyllum scalareTemperature 76°F works for Angelfish, but 77–84°F is ideal.
3.5 in · 32+ gal · 77–84°F · pH 6–7 - Fits
Tiger barb
Puntigrus tetrazonaBold, fast barbs that nip fins; great in a busy group of ten, a poor match for slow or long-finned fish.
group of 6 · 2.2 in · 32+ gal · 72–79°F · pH 6–7.5 - Fits
Amano shrimp
Caridina multidentataThe best-known algae-eating shrimp, made famous by Takashi Amano; bigger than cherries and a good fit for planted community tanks.
group of 3 · 2 in · 7+ gal · 72–77°F · pH 6.5–7.5 - Fits
Black neon tetra
Hyphessobrycon herbertaxelrodiA peaceful tetra with a bright white-over-black stripe; hardier than the neon tetra and an easy fit in any calm community tank.
group of 8 · 1.4 in · 23+ gal · 73–81°F · pH 5.5–7.5 - Fits
Blood parrot cichlid
hybridA man-made hybrid cichlid with a round body and a beak-like mouth that barely closes; usually gentle and rarely able to swallow tank mates.
7.9 in · 36+ gal · 72–82°F · pH 6.5–8 - Fits
Bristlenose pleco
Ancistrus cf. cirrhosusThe go-to glass cleaner: a compact 5-inch pleco with bushy whiskers on the males that needs a cave and vegetables, not just algae.
4.9 in · 17+ gal · 70–79°F · pH 5.5–7.5 - Fits
Bronze cory
Corydoras aeneusThe most widely kept cory: a tough bronze-green or albino catfish that shoals along the bottom and handles a broad range of water.
group of 6 · 3 in · 23+ gal · 70–81°F · pH 6–8 - Fits
Cardinal tetra
Paracheirodon axelrodipH 7.2 works for Cardinal tetra, but 4.0–6.0 is ideal.
group of 8 · 1.4 in · 17+ gal · 73–81°F · pH 4–6 - Fits
Cherry barb
Puntius titteyaOne of the most peaceful barbs: males glow cherry red and leave fins alone, making it great for planted community tanks.
group of 6 · 2 in · 17+ gal · 73–81°F · pH 6–8 - Fits
Convict cichlid
Amatitlania nigrofasciataA tough Central American cichlid that breeds almost anywhere, and is aggressive enough to attack fish several times its size.
group of 2 · 5.9 in · 34+ gal · 75–82°F · pH 7–8 - Fits
Firemouth cichlid
Thorichthys meekiA Central American cichlid with a fiery red throat it flares when threatened; fairly calm for a cichlid but territorial when breeding.
group of 2 · 4.7 in · 34+ gal · 75–82°F · pH 6.5–8.5 - Fits
Goldfish
Carassius auratusTemperature 76°F works for Goldfish, but 50–75°F is ideal.
group of 2 · 5.9 in · 24+ gal · 50–75°F · pH 6.5–8 - Fits
Jewel cichlid
Rubricatochromis bimaculatus (syn. Hemichromis bimaculatus)A blazing red West African cichlid that holds its territory year-round and turns extremely aggressive when spawning; best kept as a pair on its own.
group of 2 · 5.9 in · 34+ gal · 72–82°F · pH 6–7.8 - Fits
Pearl gourami
Trichopodus leeriiOne of the calmest and most beautiful gouramis, covered in pearly spots; ideal for a quiet planted tank with floating plants.
4.7 in · 26+ gal · 75–86°F · pH 5.5–8 - Fits
Serpae tetra
Hyphessobrycon equesA bright red, hardy tetra with a notorious fin-nipping habit; needs a big group and no slow, long-finned tank mates.
group of 12 · 1.6 in · 23+ gal · 72–79°F · pH 5–7.5 - Fits
Three spot gourami
Trichopodus trichopterusThe most common gourami: hardy, omnivorous and an air breather, though males can turn quarrelsome, especially when spawning.
5.9 in · 26+ gal · 75–86°F · pH 6–8 - Fits
Zebra danio
Danio rerioTemperature 76°F works for Zebra danio, but 64–75°F is ideal.
group of 8 · 1.5 in · 26+ gal · 64–75°F · pH 6–8 - Fits
African dwarf frog
Hymenochirus boettgeriA small, fully aquatic frog of up to 2 inches that can share a tank with peaceful fish, as long as it is target-fed.
group of 2 · 2 in · 7+ gal · 75–77°F · pH 6.6–7.8 - Fits
Assassin snail
Anentome helenaA yellow-and-brown striped predatory snail kept to control bladder, ramshorn and trumpet snails; it breeds slowly and never becomes a pest.
1 in · 3+ gal · 70–81°F · pH 7.2–8
And 26 more in the species catalog.
Possible, with care
- With care
Fancy guppy
Poecilia reticulataGH 8 dGH is outside the Fancy guppy range 8–25 dGH.
group of 3 · 1.4 in · 13+ gal · 75–81°F · pH 7–8 - With care
Betta
Betta splendensBetta: turnover 5.0/h is above the comfortable 3/h.
2.8 in · 11+ gal · 72–86°F · pH 6–7.5 - With care
Dwarf gourami
Trichogaster laliusDwarf gourami: turnover 5.0/h is above the comfortable 3/h.
3 in · 18+ gal · 72–81°F · pH 6–7.5 - With care
Glowlight tetra
Hemigrammus erythrozonusGlowlight tetra: tank width 33 cm < 38 cm needed.
group of 6 · 1.6 in · 22+ gal · 75–82°F · pH 6–7.5 - With care
Honey gourami
Trichogaster chunaHoney gourami: turnover 5.0/h is above the comfortable 3/h.
group of 4 · 2.2 in · 17+ gal · 72–81°F · pH 6–7.5 - With care
Kribensis
Pelvicachromis pulcherKribensis: tank width 33 cm < 38 cm needed.
group of 2 · 3.9 in · 23+ gal · 75–81°F · pH 6.5–7 - With care
Molly
Poecilia sphenopsGH 8 dGH is outside the Molly range 15–30 dGH.
group of 3 · 3.1 in · 26+ gal · 70–82°F · pH 7–8.5 - With care
Platy
Xiphophorus maculatusGH 8 dGH is outside the Platy range 10–30 dGH.
group of 3 · 2.4 in · 17+ gal · 68–79°F · pH 7–8.2 - With care
Rainbow shark
Epalzeorhynchos frenatumRainbow shark: needs a 243 L tank, this one is 213 L.
5.9 in · 76+ gal · 75–79°F · pH 6.5–8 - With care
Red-tailed black shark
Epalzeorhynchos bicolorRed-tailed black shark: needs a 243 L tank, this one is 213 L.
4.9 in · 76+ gal · 72–79°F · pH 6.5–7.5 - With care
Siamese algae eater
Crossocheilus oblongusSiamese algae eater: needs a 304 L tank, this one is 213 L.
5.9 in · 95+ gal · 75–79°F · pH 6.5–8 - With care
Swordtail
Xiphophorus helleriiGH 8 dGH is outside the Swordtail range 10–25 dGH.
group of 3 · 6.3 in · 34+ gal · 72–82°F · pH 7–8
And 26 more in the species catalog.
Too much
- Avoid
Black widow tetra
Gymnocorymbus ternetzipH 7.2 is outside the Black widow tetra range 6.0–7.0.
group of 12 · 2.4 in · 22+ gal · 68–79°F · pH 6–7 - Avoid
Blue dolphin cichlid
Cyrtocara mooriiTemperature 76°F is outside the Blue dolphin cichlid range 77–84°F.
group of 3 · 9.8 in · 80+ gal · 77–81°F · pH 8–8.5 - Avoid
Chinese algae eater
Gyrinocheilus aymonieriStocking of 340% is above the 150% limit.
group of 6 · 11 in · 95+ gal · 72–79°F · pH 6–8 - Avoid
Clown loach
Chromobotia macracanthuspH 7.2 is outside the Clown loach range 5.0–7.0.
group of 6 · 15.7 in · 202+ gal · 75–86°F · pH 5–7 - Avoid
Common pleco
Pterygoplichthys pardalisAmazon sailfin catfish (common pleco): needs a 650 L tank, this one is 213 L.
22.8 in · 203+ gal · 77–82°F · pH 7–7.5 - Avoid
Demasoni
Chindongo demasoni (syn. Pseudotropheus demasoni)pH 7.2 is outside the Demasoni range 7.6–8.8.
group of 6 · 3 in · 64+ gal · 75–82°F · pH 8.2–8.5 - Avoid
Discus
Symphysodon aequifasciatus (species complex)Temperature 76°F is outside the Discus range 79–86°F.
group of 5 · 5.5 in · 80+ gal · 79–86°F · pH 5–7 - Avoid
Fairy cichlid
Neolamprologus brichardipH 7.2 is outside the Fairy cichlid range 8.0–9.0.
group of 2 · 3.5 in · 34+ gal · 73–79°F · pH 8–9 - Avoid
Golden mbuna
Melanochromis auratuspH 7.2 is outside the Golden mbuna range 7.6–8.8.
group of 4 · 4.3 in · 64+ gal · 75–82°F · pH 7.6–8.8 - Avoid
Iridescent shark
Pangasianodon hypophthalmusIridescent shark: needs a 14580 L tank, this one is 213 L.
51.2 in · 4532+ gal · 72–79°F · pH 6.5–7.5 - Avoid
Kuhli loach
Pangio semicinctapH 7.2 is outside the Kuhli loach range 3.5–7.0.
group of 6 · 3.9 in · 17+ gal · 70–79°F · pH 3.5–7 - Avoid
Leopard sailfin pleco
Pterygoplichthys gibbicepspH 7.2 is outside the Leopard sailfin pleco range 5.0–7.0.
19.7 in · 187+ gal · 77–86°F · pH 5–7
And 50 more in the species catalog.
How many fish fit in 55 gallons?
The old inch-per-gallon rule ignores body shape and group size. We estimate bioload from adult mass and water temperature, compare it with what the filter and weekly water changes remove, then add the space each species needs to swim and school.
The list above checks one species at a time. To mix several, add them to your own tank: the planner checks every pair and the combined load.
Every tank is different. Set yours up once (size, water, who already lives there) and each species is checked against it.
Plan my tank