Can Gertrude's Spotted Blue-eye and Malawi Eyebiter Live Together?

Gertrude's Spotted Blue-eye is a peaceful species (2/10), while Malawi Eyebiter is semi-aggressive (8/10). This notable difference means Malawi Eyebiter may occasionally assert dominance over Gertrude's Spotted Blue-eye.

Large aggression gap (6 points) between Gertrude's Spotted Blue-eye and Malawi Eyebiter increases stress risk for the more peaceful fish.

Gertrude's Spotted Blue-eye and Malawi Eyebiter both frequent the Top (Surface) and 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.

There is a critical concern: the Nano / Bite-sized (Predation Risk) behaviour of one fish directly conflicts with the Piscivore (Eats small/nano fish) trait of the other — piscivorous fish will prey on nano-sized tank mates..

Worth noting: Gertrude's Spotted Blue-eye is a known jumper, so a tight-fitting lid is essential.

The safe temperature window for both species falls between 23°C and 28°C. Aim for the midpoint of this range (around 25.5°C) for optimal comfort.

The pH requirements of Gertrude's Spotted Blue-eye (6–7.5) and Malawi Eyebiter (7.8–8.6) do not overlap, making it impossible to satisfy both species simultaneously.

For general hardness, the shared comfort zone is 10–15 dGH. Regular testing will ensure conditions stay within this range.

To house Gertrude's Spotted Blue-eye and Malawi Eyebiter together, plan for an aquarium of at least 475 litres with a minimum length of 150 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, Plants - Floating, Leaf Litter/Blackwater, Sand (Sifters). 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.

Gertrude's Spotted Blue-eye and Malawi Eyebiter 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.