Can Fairy Cichlid (Brichardi) and Harlequin Rasbora Live Together?

Fairy Cichlid (Brichardi) is a semi-aggressive species (8/10), while Harlequin Rasbora is peaceful (1/10). This notable difference means Fairy Cichlid (Brichardi) may occasionally assert dominance over Harlequin Rasbora.

Large aggression gap (7 points) between Fairy Cichlid (Brichardi) and Harlequin Rasbora increases stress risk for the more peaceful fish.

Fairy Cichlid (Brichardi) and Harlequin 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.

The safe temperature window for both species falls between 23°C and 27°C. Aim for the midpoint of this range (around 25.0°C) for optimal comfort.

The pH requirements of Fairy Cichlid (Brichardi) (8–9) and Harlequin Rasbora (5–7.5) do not overlap, making it impossible to satisfy both species simultaneously.

For general hardness, the shared comfort zone is 10–12 dGH. Regular testing will ensure conditions stay within this range. An aquarium test kit is recommended for monitoring.

To house Fairy Cichlid (Brichardi) and Harlequin Rasbora together, plan for an aquarium of at least 132 litres with a minimum length of 75 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: Sand (Sifters), Smooth Gravel (Sensitive Barbels), Plants - Densely covered, Leaf Litter/Blackwater. 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.