Can Brevis Shelldweller and Grime Rainbowfish Live Together?

Brevis Shelldweller is a moderately assertive species (5/10), while Grime Rainbowfish is peaceful (2/10). This modest difference means Brevis Shelldweller may occasionally assert dominance over Grime Rainbowfish.

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

Worth noting: Grime 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.

The pH requirements of Brevis Shelldweller (8–9) and Grime Rainbowfish (6.8–7.8) do not overlap, making it impossible to satisfy both species simultaneously.

For general hardness, the shared comfort zone is 10–18 dGH. Regular testing will ensure conditions stay within this range.

To house Brevis Shelldweller and Grime Rainbowfish together, plan for an aquarium of at least 150 litres with a minimum length of 90 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: Sand (Sifters), Shells (Breeding/Hiding), Plants - Densely covered. 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.

Brevis Shelldweller and Grime Rainbowfish are the kind of pair that can look acceptable in a shop but become a maintenance problem at home. The main risk is not a single number in the chart; it is the way incompatible behavior, water needs, or pressure on space compounds over time once both fish are established in the same tank.