Clown Killifish: Tank Size, Tank Mates & How Many to Keep

What size tank do clown killifish need?

At least 10 gallons (38 liters) for a group of 6. The smallest standard tank that works is the 10 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: Epiplatys annulatus.

How many clown killifish in each tank size?

This is how many each standard tank carries comfortably if clown killifish are the only fish in it. Share the tank with other species and the number goes down.

Tank	How many clown killifish
5 gallon	Too small
10 gallon	up to 8
20 gallon long	up to 16
29 gallon	up to 23
40 gallon breeder	up to 32
55 gallon	up to 45
75 gallon	60 or more
125 gallon	60 or more

Check clown killifish against your own tank and other fish

Good to know

Keep at least 6. Alone or in twos and threes, clown killifish hide, stop eating well, or pick on each other.
This is a jumper. Use a lid with no gaps.

Tank mates for clown killifish

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.

Poor matches

Guppy: They need different water: Clown killifish likes a pH of 5.5–7, guppy likes 7–8.2.
Angelfish: Angelfish (about 6 in) can eat clown killifish (about 1.4 in).
Fancy goldfish: Goldfish do best with other fancy goldfish.
Oscar: Oscar is aggressive and will bully or kill peaceful fish such as clown killifish.

Questions and answers

What size tank do clown killifish need?

At least 10 gallons (38 liters) for a group of 6. The smallest standard tank that works is the 10 gallon. A bigger tank is always easier to keep stable.

How many clown killifish should be kept together?

At least 6. Clown killifish are social animals and only behave naturally in a group. More is better if the tank has room.

Can clown killifish live in a 10 gallon tank?

Yes. A 10 gallon tank carries up to about 8 as the only fish in the tank.

What temperature do clown killifish need?

73–79 °F (23–26 °C), with a pH of 5.5–7. In most homes that means a heater.

Can clown killifish live with a betta?

Usually, yes, in a tank of 10 gallons (38 liters) or more. They like the same water: 75–79 °F (24–26 °C). Every betta has its own temper, so watch closely for the first week and have a spare tank ready.

More fish

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.