Can Allen's Rainbowfish and Apistogramma Marmor (Marbled Apisto) Live Together?

Allen's Rainbowfish is a peaceful species (2/10), while Apistogramma Marmor (Marbled Apisto) is generally mild-mannered (4/10). This modest difference means Apistogramma Marmor (Marbled Apisto) may occasionally assert dominance over Allen's Rainbowfish.

In terms of spatial distribution, Allen's Rainbowfish prefers the Top (Surface) and Middle (Open Water) zones, whereas Apistogramma Marmor (Marbled Apisto) occupies the Bottom (Substrate) zone. Because they use different levels of the water column, territorial disputes are less likely and the tank will appear more balanced.

Worth noting: Allen's 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 6 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 4–10 dGH. Regular testing will ensure conditions stay within this range.

To house Allen's Rainbowfish and Apistogramma Marmor (Marbled Apisto) together, plan for an aquarium of at least 150 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 - lighly covered, Driftwood (Digestion/Hiding), Sand (Sifters), 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.