Emperor tetra care guide

Plan a tank with emperor tetrasSee all tank mates

Emperor tetra quick facts

Tank setup

Give a group of six at least a 20-gallon long tank (76 L, 75 cm / 30 in). Go bigger if you keep several males. Use plenty of plants, some wood and a dark substrate so their colors show, and leave open water in the middle for swimming. Gentle to moderate flow suits them.

How many emperor tetras in a tank?

The smallest common tank that suits emperor tetras is a 20 gallon long. Here is roughly how many fit in each size when they are the only fish, based on adult size and waste output. Leave room if you want tank mates.

Water parameters

Aim for 23–27 °C (73–81 °F), pH 5.5–7.5 and soft to moderately hard water (2–12 dGH). Farm-bred fish adapt well, but colors are best in softer, slightly acidic water. They dislike rising nitrate, so change 25–30% of the water every week.

Best tank mates for emperor tetras

These popular species share emperor tetras' water needs and temperament. See the full list of 99 good matches.

• Betta fish

  6.5 cm (2.6 in) · 24–28°C (75–82°F)

• Cherry shrimp

  3 cm (1.2 in) · 20–27°C (68–81°F)

• Nerite snail

  2.5 cm (1 in) · 22–27°C (72–81°F)

• Guppy

  5 cm (2 in) · 22–27°C (72–81°F)

• Dwarf gourami

  7.5 cm (3 in) · 24–28°C (75–82°F)

• Neon tetra

  3.5 cm (1.4 in) · 21–25°C (70–77°F)

• Panda corydoras

  4.5 cm (1.8 in) · 21–25°C (70–77°F)

• Bristlenose pleco

  12 cm (4.7 in) · 22–26°C (72–79°F)

Avoid keeping emperor tetras with

• Common goldfish: They need different temperatures: Emperor tetra 23–27°C (73–81°F), common goldfish 15–22°C (59–72°F).
• Oscar: Oscar can eat emperor tetras: they're small enough to fit in its mouth once it's grown.
• Bala shark: Bala shark can eat emperor tetras: they're small enough to fit in its mouth once it's grown.
• Chinese algae eater: Chinese algae eater is aggressive and will bully or injure peaceful emperor tetras.
• Convict cichlid: Convict cichlid is aggressive and will bully or injure peaceful emperor tetras.
• Discus: They need different temperatures: Emperor tetra 23–27°C (73–81°F), discus 28–30°C (82–86°F).

Feeding

In the wild they snap up small insects, worms and tiny crustaceans. Use a quality flake or micro pellet as the base. Add frozen or live daphnia, brine shrimp and bloodworm several times a week for the best color.

Behavior

Peaceful toward other species and a good mid-water community fish. Each male claims a small spot and displays or spars with rival males, but in a roomy, planted tank this rarely causes injuries. Keep more females than males to spread out the attention. Avoid tankmates big enough to swallow them.

Breeding

Egg scatterers that give no parental care. Move a well-fed pair to a small, dim tank with java moss or a spawning mop, soft and slightly acidic water and a sponge filter. Remove the adults after spawning because they eat the eggs. Fry hatch in 1–1.5 days and need infusoria first, then baby brine shrimp or microworms.

Tips from experienced keepers

• Keep one male for every two or three females to cut down on sparring.
• Males have a trident-shaped tail with a long middle ray. Females are smaller with plain fins.
• Dark substrate, plants and floating cover make the purple and blue colors much stronger.
• Good tankmates: corydoras, pencilfish, small rasboras, other peaceful tetras and dwarf cichlids.
• Do not skip weekly water changes. Colors fade and fish hide when nitrate builds up.

Sources

We checked these references when writing this page. Values are for healthy long-term keeping, not survival limits. Last reviewed 2026-10-13. See our editorial policy.

• seriouslyfish.com
• fishbase.se
• fishkeeper.co.uk