Can Cardinal Tetra and Telmatochromis dhonti Live Together?

Cardinal Tetra is a peaceful species (1/10), while Telmatochromis dhonti is semi-aggressive (8/10). This notable difference means Telmatochromis dhonti may occasionally assert dominance over Cardinal Tetra.

Large aggression gap (7 points) between Cardinal Tetra and Telmatochromis dhonti increases stress risk for the more peaceful fish.

In terms of spatial distribution, Cardinal Tetra prefers the Middle (Open Water) zone, whereas Telmatochromis dhonti 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.

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

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 Cardinal Tetra (4–7) and Telmatochromis dhonti (7.8–9) do not overlap, making it impossible to satisfy both species simultaneously.

Hardness requirements are incompatible: Cardinal Tetra needs 1–8 dGH while Telmatochromis dhonti requires 10–25 dGH.

To house Cardinal Tetra and Telmatochromis dhonti together, plan for an aquarium of at least 120 litres with a minimum length of 80 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: Leaf Litter/Blackwater, Driftwood (Digestion/Hiding), Plants - Densely covered, Sand (Sifters), Shells (Breeding/Hiding). Meeting these requirements will help both species thrive.

Both species do well with low (still water) water movement, so a standard filtration setup rated for the tank volume should suffice.

Cardinal Tetra and Telmatochromis dhonti 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.