Can Arapaima and Trout Cichlid (Champsochromis) Live Together?

Both Arapaima and Trout Cichlid (Champsochromis) are semi-aggressive species with an aggression score of 7/10. Their matching temperaments mean neither fish is likely to dominate the other in a shared aquarium.

Both Arapaima and Trout Cichlid (Champsochromis) are highly aggressive, increasing the risk of violent confrontations.

Arapaima and Trout Cichlid (Champsochromis) both frequent the Top (Surface) and Middle (Open Water) region of the setup. This overlap can increase competition for space, so providing ample room and cover is important to keep both species comfortable.

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

The safe temperature window for both species falls between 24°C and 28°C. Aim for the midpoint of this range (around 26.0°C) for optimal comfort.

The pH requirements of Arapaima (6–7.5) and Trout Cichlid (Champsochromis) (7.8–8.6) do not overlap, making it impossible to satisfy both species simultaneously.

For general hardness, the shared comfort zone is 10–15 dGH. Regular testing will ensure conditions stay within this range.

To house Arapaima and Trout Cichlid (Champsochromis) together, plan for an aquarium of at least 15000 litres with a minimum length of 600 cm. This recommendation combines the stricter species minimums with a community-load allowance so the pairing has realistic long-term space and filtration headroom.

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: Sand (Sifters). 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.

Arapaima and Trout Cichlid (Champsochromis) are the kind of pair that can look acceptable in a shop but become a maintenance problem at home. The main risk is not a single number in the chart; it is the way incompatible behavior, water needs, or pressure on space compounds over time once both fish are established in the same tank.