What fish can live with Clown Killifish?

Use the "Often compatible" lists as a shortlist, not a stocking plan. Always run the pair tool and check the footprint of your actual tank first. Verify behaviour for Clown Killifish against your own reading before you buy.

What tank mates should you avoid with Clown Killifish?

Avoid Oscar, Jack Dempsey, Common Pleco based on size, temperament, or predation risk on file.

What size tank do Clown Killifish need for a community?

20L is the planning floor for adult swimming space and bioload headroom. Long-term, a 30L+ tank lets adults use the full footprint without crowding the next species. Footprint, meaning length and front-to-back depth, matters as much as raw volume for active or territorial species.

Clown Killifish tank mates

The nano surface fish that works in shrimp tanks. Soft acidic blackwater plus micro-food, and the colony settles in a 30L planted cube.

Evidence: partially verified

Confidence: medium

Lists below are built from this species record (safest, best with, risky, unsafe) — each link opens a pair-level check, not a guarantee.

← Full Clown Killifish profile·Compatibility checker·Tank builder·More oddball

Best tank mates (on file)

Merged from conservative safest and best with fields — de-duplicated by species.

Cherry Shrimp Pair check
The Clown Killifish profile lists Cherry Shrimp as both safe and a recommended pairing. Cherry Shrimp schools in groups of 10 or more, so plan room for the whole group rather than one fish. Cherry Shrimp swims in the bottom zone while Clown Killifish stays in the top, so the two will not crowd the same water column.
Chili Rasbora Pair check
The Clown Killifish profile lists Chili Rasbora as both safe and a recommended pairing. Chili Rasbora schools in groups of 8 or more, so plan room for the whole group rather than one fish. Chili Rasbora swims in the middle zone while Clown Killifish stays in the top, so the two will not crowd the same water column.
Corydoras Catfish Pair check
The Clown Killifish profile lists Corydoras Catfish as both safe and a recommended pairing. Corydoras Catfish schools in groups of 6 or more, so plan room for the whole group rather than one fish. Corydoras Catfish swims in the bottom zone while Clown Killifish stays in the top, so the two will not crowd the same water column.
Ember Tetra Pair check
The Clown Killifish profile lists Ember Tetra as both safe and a recommended pairing. Ember Tetra schools in groups of 8 or more, so plan room for the whole group rather than one fish. Ember Tetra swims in the middle zone while Clown Killifish stays in the top, so the two will not crowd the same water column.
Otocinclus Pair check
The Clown Killifish profile lists Otocinclus as both safe and a recommended pairing. Otocinclus schools in groups of 4 or more, so plan room for the whole group rather than one fish. Otocinclus swims in the bottom zone while Clown Killifish stays in the top, so the two will not crowd the same water column.

Risky or situational

From risky tank mates and broad avoid with (excluding “unsafe” below). May work with species-only setups, more water, or mature systems — read the pair page.

Dwarf Gourami Open pair check
Marked risky or situational on the profile. Tank length and group size change the outcome more than a temperament label does.

Fish to avoid with Clown Killifish

From the unsafe list — predation, aggression, or space rules on this profile.

Oscar See why (pair)
Oscar reaches 35cm and is flagged predatory. Clown Killifish at 3.5cm is prey-sized for it. Oscar needs at least 300L, far above the 20L minimum for Clown Killifish. The tank that houses one stresses the other. Oscar is rated aggressive and Clown Killifish is rated peaceful. No community-style planning carries that gap.
Jack Dempsey See why (pair)
Jack Dempsey reaches 25cm and is flagged predatory. Clown Killifish at 3.5cm is prey-sized for it. Jack Dempsey needs at least 200L, far above the 20L minimum for Clown Killifish. The tank that houses one stresses the other. Jack Dempsey is rated aggressive and Clown Killifish is rated peaceful. No community-style planning carries that gap.
Common Pleco See why (pair)
Common Pleco needs at least 600L, far above the 20L minimum for Clown Killifish. The tank that houses one stresses the other.

Tank size and groups

Published minimum for Clown Killifish: 20L — group minimum 6 (schooling).
Compatibility changes when the tank is too short for turning, too little for a real school, or too warm for one species and not the other — that is why pair checks include tank context, not only temperament.
Nearest litre hub to this minimum: 30L hub.

Plan before you buy

Pair checks for every mix, then multi-species stocking in the builder.

Open compatibility checker Tank builder

Filtration & heating

A 20L minimum tank for Clown Killifish needs a filter rated for at least 80L/hr turnover and a heater maintaining 22–28°C.

Filter buying guide →Heater buying guide →Beginner plants guide →