reefcalcs

Tank size · Freshwater

What size tank for a Clown killifish? (10 gal minimum)

Clown killifish (Epiplatys annulatus) — adult 1.4″, slim-bodied, schooling.

The three sizes — minimum, good, ideal

TierTank sizeWhat it gets you
Absolute minimum10 US galSurvives adult life. No extras — no tankmates beyond the essentials, no aquascape that eats footprint.
Good15 US galRoom for a small community, decor, and parameter buffering. This is where most people should aim.
Ideal25 US galNatural-feeling space. Active swimmers stop pacing, schoolers school freely, aggression drops.

Parameters at a glance

Temperature
68–77 °F
pH
5.5–7
Adult size
1.4″
Body type
slim

Why tank size matters for this species

Clown killifish is a schooling species — keep at least 8 together. The tank-size minimum above assumes that group. A single or pair-only setup stresses the fish, dulls colour, and shortens lifespan.

Common mistake

Leaving the tank uncovered.

Source for the tank-size minimum

Seriously Fish Epiplatys annulatus profile: 45 × 30 cm base, group of 8–10; Practical Fishkeeping gives 45 × 30 × 20 cm.

Next steps

People also ask

What is the absolute minimum tank size for a Clown killifish?
10 US gallons as an adult, no strict footprint requirement. Seriously Fish Epiplatys annulatus profile: 45 × 30 cm base, group of 8–10; Practical Fishkeeping gives 45 × 30 × 20 cm.
Can I keep a Clown killifish in a smaller tank when it's a juvenile?
Briefly, yes — fish stores often sell juveniles that haven't reached adult size yet. But you should plan, buy, and cycle the adult-minimum tank from day one. Upgrading mid-life stresses the fish and is far more expensive than buying the right tank up front.
Do Clown killifish need to be in a group?
Yes — they're schooling. A group of at least 8 together. Single or pair-only setups stress them, dull their colour, and shorten their lifespan. Plan tank size for the school, not the individual.
What temperature and pH does a Clown killifish need?
Temperature 68–77 °F, pH 5.5–7.
What's the most common mistake people make with Clown killifish?
Leaving the tank uncovered.

Last reviewed