Can Black Phantom Tetra and Duboisi Cichlid (Tropheus) Live Together?

Black Phantom Tetra 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 Black Phantom Tetra.

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

Black Phantom Tetra and Duboisi Cichlid (Tropheus) 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.

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.

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 Black Phantom Tetra (5–7.5) and Duboisi Cichlid (Tropheus) (8–9) 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 Black Phantom Tetra and Duboisi Cichlid (Tropheus) together, plan for an aquarium of at least 280 litres with a minimum length of 120 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), 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 Black Phantom Tetra'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 Black Phantom Tetra 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 Black Phantom Tetra receives an adequate share.