Can Malawi Eyebiter and San Juan Cory Live Together?

Malawi Eyebiter is a semi-aggressive species (8/10), while San Juan Cory is peaceful (0/10). This notable difference means Malawi Eyebiter may occasionally assert dominance over San Juan Cory.

Large aggression gap (8 points) between Malawi Eyebiter and San Juan Cory increases stress risk for the more peaceful fish.

In terms of spatial distribution, Malawi Eyebiter prefers the Top (Surface) and Middle (Open Water) zones, whereas San Juan Cory 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: Malawi Eyebiter is a known jumper, so a tight-fitting lid is essential.

The safe temperature window for both species falls between 23°C and 26°C. Aim for the midpoint of this range (around 24.5°C) for optimal comfort.

The pH requirements of Malawi Eyebiter (7.8–8.6) and San Juan Cory (6–7.5) 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 Malawi Eyebiter and San Juan Cory 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: Sand (Sifters), Plants - Densely covered, Smooth Gravel (Sensitive Barbels). 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.

Malawi Eyebiter and San Juan Cory 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.