I have a 5-gallon tank. What can I keep?
A 5-gallon tank is a nano tank: small enough that waste builds up fast, so it suits a single betta or a colony of cherry shrimp rather than a school of fish.
A 5-gallon tank holds about 19 L. 3 of the 14 species we cover fit it so far; we add more every week.
Fits a 5-gallon tank, and how many
| Species | How many fit on their own | Adult size | Smallest tank |
|---|---|---|---|
| Betta fish | 1 | 2.5–2.8 in | 5 gallons (19 L) |
| Cherry shrimp | Up to about 10 (at least 6) | 1–1.5 in | 5 gallons (19 L) |
| Zebra nerite snail | Up to about 1 | 1 in | 5 gallons (19 L) |
Counts are each species on its own, from our crowding model. Mixing species shares the space, so fewer of each fit: plan a mixed tank in the compatibility checker. Each species page says whether its count matches a published stocking list or is a cautious estimate.
Pairs that live well together in 5 gallons
Both species fit a 5-gallon tank on their own and every compatibility check passes at this size. This is about the two species getting along, not a stocking plan.
No two species we cover get a clean yes together at this size yet. A single species, or one fish plus shrimp or snails, is the safer plan.
Too big for 5 gallons
- Angelfish: angelfish need at least 30 gallons.
- Bronze corydoras: bronze corydoras need at least 20 gallons.
- Common goldfish: common goldfish need at least 75 gallons.
- Ember tetra: ember tetras need at least 10 gallons.
- Fancy goldfish: fancy goldfish need at least 20 gallons.
- Guppy: guppies need at least 10 gallons.
- Neon tetra: neon tetras need at least 10 gallons.
- Panda corydoras: panda corydoras need at least 10 gallons.
- Platy: platies need at least 20 gallons.
- Pygmy corydoras: pygmy corydoras need at least 10 gallons.
- Tiger barb: tiger barbs need at least 30 gallons.
Before you buy fish
Cycle the tank first and check it’s ready, then use the compatibility checker to test your plan.