What size tank do red-eye tetras need?
At least 27 gallons (103 liters) for a group of 6. The smallest standard tank that works is the 29 gallon. A bigger tank is always easier to keep stable. We give the size for an adult fish in a proper group, because the small fish in the shop will grow. Scientific name: Moenkhausia sanctaefilomenae.
How many red-eye tetras in each tank size?
This is how many each standard tank carries comfortably if red-eye tetras are the only fish in it. Share the tank with other species and the number goes down.
| Tank | How many red-eye tetras |
|---|---|
| 5 gallon | Too small |
| 10 gallon | Too small |
| 20 gallon long | Too small |
| 29 gallon | up to 9 |
| 40 gallon breeder | up to 13 |
| 55 gallon | up to 18 |
| 75 gallon | up to 24 |
| 125 gallon | up to 40 |
Check red-eye tetras against your own tank and other fish
Good to know
- A busy fish that can nip fins. Keep a proper school and avoid slow, long-finned tankmates.
- Keep at least 6. Alone or in twos and threes, red-eye tetras hide, stop eating well, or pick on each other.
- It nips fins. Avoid slow tankmates with long, flowing fins.
Tank mates for red-eye tetras
These animals like the same water, are a safe size, and have a temper that fits. It is a match on paper: always watch new tankmates for the first week.
- Bristlenose pleco
- Keyhole cichlid
- Rainbow cichlid
- Bronze corydoras
- Bloodfin tetra
- Julii corydoras
- Glowlight danio
- Bandit corydoras
Poor matches
- Betta: Red-eye tetra nips fins and betta has long fins. Avoid this pair.
- Fancy goldfish: Goldfish do best with other fancy goldfish.
- Oscar: Oscar (about 12 in) can eat red-eye tetra (about 2.8 in).
Questions and answers
What size tank do red-eye tetras need?
At least 27 gallons (103 liters) for a group of 6. The smallest standard tank that works is the 29 gallon. A bigger tank is always easier to keep stable.
How many red-eye tetras should be kept together?
At least 6. Red-eye tetras are social animals and only behave naturally in a group. A group of 8 or more is better if the tank has room.
Can red-eye tetras live in a 10 gallon tank?
No. Red-eye tetra needs at least 27 gallons (103 liters).
What temperature do red-eye tetras need?
72–79 °F (22–26 °C), with a pH of 6–8. In most homes that means a heater.
Can red-eye tetras live with a betta?
It is not a good match. Red-eye tetra nips fins and betta has long fins. Avoid this pair.
More fish
- African dwarf frog
- Flame tetra
- Penguin tetra
- Head-and-tail-light tetra
- Pearl danio
- Glowlight danio
- All 150 species
Adult size, tank size and water ranges follow the mainstream care consensus (Seriously Fish species profiles and FishBase maximum lengths). Where sources differ we use the more cautious figure. Stocking numbers come from our stocking calculator.