Can Brilliant Rummy-Nose Tetra and Cuckoo Catfish Live Together?

Brilliant Rummy-Nose Tetra is a peaceful species (1/10), while Cuckoo Catfish is moderately assertive (5/10). This notable difference means Cuckoo Catfish may occasionally assert dominance over Brilliant Rummy-Nose Tetra.

Brilliant Rummy-Nose Tetra and Cuckoo Catfish both frequent the Middle (Open Water) and Bottom (Substrate) 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: Cuckoo Catfish is nocturnal and will be most active after lights-out, naturally reducing daytime encounters.

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 Brilliant Rummy-Nose Tetra (5–7) and Cuckoo Catfish (7.5–9) do not overlap, making it impossible to satisfy both species simultaneously.

Hardness requirements are incompatible: Brilliant Rummy-Nose Tetra needs 1–8 dGH while Cuckoo Catfish requires 10–25 dGH.

To house Brilliant Rummy-Nose Tetra and Cuckoo Catfish together, plan for an aquarium of at least 340 litres with a minimum length of 120 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: Plants - Densely covered, Leaf Litter/Blackwater, 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.