Can Clown Killifish and Duboisi Cichlid (Tropheus) Live Together?

Clown Killifish is a peaceful species (2/10), while Duboisi Cichlid (Tropheus) is semi-aggressive (8/10). This notable difference means Duboisi Cichlid (Tropheus) may occasionally assert dominance over Clown Killifish.

Large aggression gap (6 points) between Clown Killifish and Duboisi Cichlid (Tropheus) increases stress risk for the more peaceful fish.

In terms of spatial distribution, Clown Killifish prefers the Top (Surface) zone, whereas Duboisi Cichlid (Tropheus) occupies the Middle (Open Water) and Bottom (Substrate) zones. 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: Hyperactive swimmers can stress shy, slow-moving species through constant motion. Aggressive eaters may outcompete shy fish for food, leading to malnutrition.

Worth noting: Clown Killifish is a known jumper, so a tight-fitting lid is essential.

The safe temperature window for both species falls between 24°C and 27°C. Aim for the midpoint of this range (around 25.5°C) for optimal comfort.

The pH requirements of Clown Killifish (5–7) and Duboisi Cichlid (Tropheus) (8–9) do not overlap, making it impossible to satisfy both species simultaneously.

Hardness requirements are incompatible: Clown Killifish needs 1–8 dGH while Duboisi Cichlid (Tropheus) requires 10–25 dGH. An aquarium test kit is recommended for monitoring.

To house Clown Killifish and Duboisi Cichlid (Tropheus) together, plan for an aquarium of at least 336 litres with a minimum length of 120 cm. This accounts for the larger species' space requirements with an additional 20 % buffer to reduce territorial tension.

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 - Floating, Plants - Densely covered, Leaf Litter/Blackwater, Sand (Sifters), Established Algae (Otocinclus), Smooth Gravel (Sensitive Barbels). Meeting these requirements will help both species thrive.

Note a potential conflict in setup requirements: Duboisi Cichlid (Tropheus) is a plant destroyer, which conflicts with Clown Killifish's requirement for live plants. Compromise where possible or prioritise the more critical need.

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

Feeding time deserves special attention with this pairing. Duboisi Cichlid (Tropheus) is an aggressive eater that may prevent Clown Killifish from getting enough food.

Because Duboisi Cichlid (Tropheus) is a fast, competitive feeder, consider using sinking pellets or feeding at opposite ends of the setup to ensure Clown Killifish receives an adequate share.