Can American Grass Shrimp and MacCulloch's Rainbowfish (Dwarf Rainbowfish) Live Together?

American Grass Shrimp 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 American Grass Shrimp.

American Grass Shrimp 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: American Grass Shrimp is a known jumper, so a tight-fitting lid is essential.

The safe temperature window for both species falls between 20°C and 28°C. Aim for the midpoint of this range (around 24.0°C) for optimal comfort.

Both fish can tolerate a pH between 6.5 and 8. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 5–15 dGH. Regular testing will ensure conditions stay within this range.

To house American Grass Shrimp 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.