How many fish in a 3 gallon tank?
Nano tanks this small are best for shrimp, snails or a single betta.
A 3 gallon tank (11 L) is too small for any fish, shrimp or snail in our database. Water this small swings quickly in temperature and quality, so we recommend at least 5 gallons (19 L), even for a betta, shrimp or snails.
Fish that suit a 3 gallon tank
The number is the most you could keep of that species alone, by bioload. Mix species and you'll need fewer of each.
| Species | Adult size | Keep |
|---|
Fish that need a bigger tank
- Angelfish: at least 29 gallons (110 L)
- Betta fish: at least 5 gallons (19 L)
- Bristlenose pleco: at least 20 gallons (76 L)
- Bronze corydoras: at least 20 gallons (76 L)
- Cherry shrimp: at least 5 gallons (19 L)
- Common goldfish: at least 75 gallons (284 L)
- Common pleco: at least 150 gallons (568 L)
- Dwarf gourami: at least 15 gallons (57 L)
- Fancy goldfish: at least 20 gallons (76 L)
- Guppy: at least 10 gallons (38 L)
Frequently asked questions
How many fish can go in a 3 gallon tank?
A 3 gallon tank (11 L) is too small for any fish, shrimp or snail in our database. Water this small swings quickly in temperature and quality, so we recommend at least 5 gallons (19 L), even for a betta, shrimp or snails.
What are the best fish for a 3 gallon tank?
None: we recommend at least 5 gallons (19 L) for any fish, shrimp or snail. A betta, a few shrimp or a nerite snail all do better in 5 gallons or more.
How big is a 3 gallon tank?
A standard 3 gallon tank is about 12 × 8 × 10 inches (30 × 20 × 25 cm). Full of water it weighs at least 25 lb (11 kg) before glass, gravel and decor.
What fish should not go in a 3 gallon tank?
Angelfish, bettas, bristlenose plecos, bronze corydoras and cherry shrimp need more room. For example, angelfish need at least 29 gallons (110 L).