Can Peacock Bass Monoculus and Rummynose Rasbora Live Together?

Peacock Bass Monoculus is a semi-aggressive species (8/10), while Rummynose Rasbora is peaceful (2/10). This notable difference means Peacock Bass Monoculus may occasionally assert dominance over Rummynose Rasbora.

Large aggression gap (6 points) between Peacock Bass Monoculus and Rummynose Rasbora increases stress risk for the more peaceful fish.

Peacock Bass Monoculus and Rummynose Rasbora 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.

There is a critical concern: the Piscivore (Eats small/nano fish) behaviour of one fish directly conflicts with the Nano / Bite-sized (Predation Risk) trait of the other — piscivorous fish will prey on nano-sized tank mates..

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 25°C. Aim for the midpoint of this range (around 24.5°C) for optimal comfort.

Both fish can tolerate a pH between 7.3 and 7.5. Maintaining a stable value within this band is more important than hitting an exact number.

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

To house Peacock Bass Monoculus and Rummynose Rasbora 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), Driftwood (Digestion/Hiding), Plants - Densely covered. 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.

Peacock Bass Monoculus and Rummynose Rasbora 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.