Can Clown Killifish and Discus Live Together?

Clown Killifish is a peaceful species (2/10), while Discus is generally mild-mannered (4/10). This modest difference means Discus may occasionally assert dominance over Clown Killifish.

In terms of spatial distribution, Clown Killifish prefers the Top (Surface) zone, whereas Discus occupies the Middle (Open Water) and Bottom (Substrate) zones. Because they use different levels of the water column, territorial disputes are less likely and the tank will appear more balanced.

Additional behavioural considerations to keep in mind: Shrimp eaters may also prey on very small nano fish.

Worth noting: Clown Killifish is a known jumper, so a tight-fitting lid is essential.

There is no temperature overlap between Clown Killifish (23–27°C) and Discus (28–32°C). This fundamental mismatch makes long-term cohabitation impractical.

Both fish can tolerate a pH between 5 and 7. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 1–8 dGH. Regular testing will ensure conditions stay within this range. An aquarium test kit is recommended for monitoring.

To house Clown Killifish and Discus together, plan for an aquarium of at least 300 litres with a minimum length of 120 cm. This accounts for the larger species' space requirements with an additional 20 % buffer to reduce territorial tension.

Providing a mix of open swimming space and sheltered areas with rocks, driftwood, or plants will keep both species comfortable and allow natural behaviour.

Specific environmental needs for this combination include: Plants - Floating, Plants - Densely covered, Leaf Litter/Blackwater, Sand (Sifters), Driftwood (Digestion/Hiding). Meeting these requirements will help both species thrive.

Both species do well with low (still water) water movement, so a standard filtration setup rated for the tank volume should suffice.

Feeding time deserves special attention with this pairing. Discus is a known shrimp eater and may prey on small invertebrates or nano fish like Clown Killifish.