Can Malawi Eyebiter and Red Phantom Tetra Live Together?

Malawi Eyebiter is a semi-aggressive species (8/10), while Red Phantom Tetra is peaceful (1/10). This notable difference means Malawi Eyebiter may occasionally assert dominance over Red Phantom Tetra.

Large aggression gap (7 points) between Malawi Eyebiter and Red Phantom Tetra increases stress risk for the more peaceful fish.

Malawi Eyebiter and Red Phantom Tetra 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.

There are critical concerns: the Piscivore (Eats small/nano fish) behaviour of one fish directly conflicts with the Nano / Bite-sized (Predation Risk) trait of the other — piscivorous fish will prey on nano-sized tank mates.. Additionally, the Eye Biter (Attacks slow moving fish) behaviour of one fish directly conflicts with the Shy / Slow Moving (Easily Stressed) trait of the other — eye biters attack slow-moving fish, risking permanent injury..

Additional behavioural considerations to keep in mind: Aggressive fish may bully and stress shy, slow-moving species.

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 24°C. Aim for the midpoint of this range (around 23.5°C) for optimal comfort.

The pH requirements of Malawi Eyebiter (7.8–8.6) and Red Phantom Tetra (4.5–7.5) do not overlap, making it impossible to satisfy both species simultaneously.

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

To house Malawi Eyebiter and Red Phantom Tetra 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, Plants - Floating, 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.

Malawi Eyebiter and Red Phantom Tetra 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.