Can Brilliant Rummy-Nose Tetra and MacCulloch's Rainbowfish (Dwarf Rainbowfish) Live Together?

Brilliant Rummy-Nose Tetra is a peaceful species (1/10), while MacCulloch's Rainbowfish (Dwarf Rainbowfish) is peaceful (2/10). This modest difference means MacCulloch's Rainbowfish (Dwarf Rainbowfish) may occasionally assert dominance over Brilliant Rummy-Nose Tetra.

Brilliant Rummy-Nose Tetra and MacCulloch's Rainbowfish (Dwarf Rainbowfish) 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.

Worth noting: MacCulloch's Rainbowfish (Dwarf Rainbowfish) 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.

Both fish can tolerate a pH between 5.5 and 7. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 5–8 dGH. Regular testing will ensure conditions stay within this range.

To house Brilliant Rummy-Nose Tetra and MacCulloch's Rainbowfish (Dwarf Rainbowfish) together, plan for an aquarium of at least 80 litres with a minimum length of 80 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. 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.