TankBud

Flag tetra

Hyphessobrycon heterorhabdus

Also known as Belgian flag tetra

FreshwaterFish

Flag tetra (Hyphessobrycon heterorhabdus)
Carl H. Eigenmann · Public domain

Care at a glance

Temperature
70–81°F
21–27°C
pH
5.5–7.0
Adult size
1.4 in
3.5 cm
Minimum tank
16 gal
60 L
Temperament
Peaceful
Social behavior
Schooling
Swim level
Middle
Difficulty
Medium
Breeding
Egg scatterer · Medium
Rarity
Rare
Family
Characidae
Origin
Colombia, Brazil

Overview

The flag tetra is a peaceful schooling tetra for a planted community tank. It is moderately demanding to keep.

Did you know

The flag tetra's red and gold stripe works as a water-quality readout. The line glows bright when conditions are clean and stable, but stress, poor water or a harsh bare tank make it fade fast.

Caring for the flag tetra

Keep flag tetras in a group of at least six to eight, so they school and feel safe. Give the school at least 16 gal (60 L), with plants, driftwood, dim lighting and a darker substrate.

They are a bit sensitive to water quality, so keep conditions stable with steady maintenance. Aim for soft water on the acidic side, at 70 to 81°F (21 to 27°C) and a pH of 5.5 to 7.0. A dull flag tetra is often telling you to check the tank before it looks sick.

Feed quality flake, small pellets and frozen foods such as bloodworm or daphnia. Flag tetras are peaceful midwater fish that suit a community tank.

They scatter their eggs among fine-leaved plants and give no parental care. Breeding them is moderately demanding.

Good to know

The flag tetra is a characin in the family Characidae. A gold-over-red line runs the length of its body with a black stripe beneath it, and that pairing gives the flag its name.

In the wild

Flag tetras live in the lower Amazon basin across Colombia and Brazil, in slow streams, rivers and flooded forest. The water is soft and slightly acidic, shaded by the canopy and often stained with tannins over leaf litter.

Weekly picks

Tank mates

The flag tetra is a peaceful, schooling species that keeps to the middle. These picks share a community profile with it, are safe together in both directions, and overlap on water type, temperature and pH.

Check the full mix in the stocking calculator

Common questions

What size tank does a flag tetra need?

A flag tetra needs at least 16 gal (60 L). It spends most of its time in the middle.

What temperature and pH does a flag tetra need?

A flag tetra is comfortable at 70–81°F (21–27°C) with a pH of 5.5–7.0.

What does a flag tetra eat?

A flag tetra eats quality flake, small pellets and frozen foods such as bloodworm or daphnia.

How big does a flag tetra get?

An adult flag tetra reaches about 1.4 in (3.5 cm).

Does a flag tetra need a group?

Yes. A flag tetra is a schooling species and should be kept in a group, not singly.

How does a flag tetra breed?

Flag tetras scatter their eggs among fine-leaved plants and give no parental care. Breeding them is moderately demanding.

Related species