Can Fairy Cichlid (Brichardi) and Peacock Bass Monoculus Live Together?

Both Fairy Cichlid (Brichardi) and Peacock Bass Monoculus are semi-aggressive species with an aggression score of 8/10. Their matching temperaments mean neither fish is likely to dominate the other in a shared aquarium.

Both Fairy Cichlid (Brichardi) and Peacock Bass Monoculus are highly aggressive, increasing the risk of violent confrontations.

Fairy Cichlid (Brichardi) and Peacock Bass Monoculus both frequent the 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.

Additional behavioural considerations to keep in mind: Two territorial species may clash over territory, especially in smaller tanks. Two aggressive species housed together increases risk of fighting.

Worth noting: Peacock Bass Monoculus is a known jumper, so a tight-fitting lid is essential.

The safe temperature window for both species falls between 24°C and 27°C. Aim for the midpoint of this range (around 25.5°C) for optimal comfort.

The pH requirements of Fairy Cichlid (Brichardi) (8–9) and Peacock Bass Monoculus (5.5–7.5) 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 Fairy Cichlid (Brichardi) and Peacock Bass Monoculus together, plan for an aquarium of at least 1000 litres with a minimum length of 240 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), Smooth Gravel (Sensitive Barbels), Driftwood (Digestion/Hiding). Meeting these requirements will help both species thrive.

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

Fairy Cichlid (Brichardi) and Peacock Bass Monoculus 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.