Serpae Tetra: Tank Size, Tank Mates and How Many to Keep

Serpae tetras are deep red and full of energy. They squabble among themselves and nip fins, so keep a big group and avoid slow, long-finned tankmates.

Adult size
1.8 in4.5 cm
Smallest tank
20 gallons76 liters
How many
8 or more
Temperature
72–81 °F22–27 °C
pH
5.5–7.5
Temperament
Semi-aggressive
Swims
In the middle
Heater needed
Yes

What size tank do serpae tetras need?

At least 20 gallons (76 liters) for a group of 8. The smallest standard tank that works is the 20 gallon high. 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: Hyphessobrycon eques.

How many serpae tetras in each tank size?

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

TankHow many serpae tetras
5 gallonToo small
10 gallonToo small
20 gallon longup to 10
29 gallonup to 14
40 gallon breederup to 20
55 gallonup to 28
75 gallonup to 38
125 gallon60 or more

Check serpae tetras against your own tank and other fish

Good to know

  • Keep at least 8. Alone or in twos and threes, serpae tetras hide, stop eating well, or pick on each other.
  • It nips fins. Avoid slow tankmates with long, flowing fins.

Tank mates for serpae 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.

Poor matches

  • Betta: Serpae 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 serpae tetra (about 1.8 in).
  • Molly: They need different water: Serpae tetra likes a pH of 5.5–7.5, molly likes 7.5–8.5.

Questions and answers

What size tank do serpae tetras need?

At least 20 gallons (76 liters) for a group of 8. The smallest standard tank that works is the 20 gallon high. A bigger tank is always easier to keep stable.

How many serpae tetras should be kept together?

At least 8. Serpae tetras are social animals and only behave naturally in a group. More is better if the tank has room.

Can serpae tetras live in a 10 gallon tank?

No. Serpae tetra needs at least 20 gallons (76 liters).

What temperature do serpae tetras need?

72–81 °F (22–27 °C), with a pH of 5.5–7.5. In most homes that means a heater.

Can serpae tetras live with a betta?

It is not a good match. Serpae tetra nips fins and betta has long fins. Avoid this pair.

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.