Can Apistogramma Marmor (Marbled Apisto) and Flowerhorn Cichlid Live Together?

Apistogramma Marmor (Marbled Apisto) is a generally mild-mannered species (4/10), while Flowerhorn Cichlid is highly aggressive (10/10). This notable difference means Flowerhorn Cichlid may occasionally assert dominance over Apistogramma Marmor (Marbled Apisto).

Large aggression gap (6 points) between Apistogramma Marmor (Marbled Apisto) and Flowerhorn Cichlid increases stress risk for the more peaceful fish.

Apistogramma Marmor (Marbled Apisto) and Flowerhorn Cichlid both frequent the Bottom (Substrate) 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: Two territorial species may clash over territory, especially in smaller tanks.

The safe temperature window for both species falls between 26°C and 28°C. Aim for the midpoint of this range (around 27.0°C) for optimal comfort.

The pH requirements of Apistogramma Marmor (Marbled Apisto) (5.5–7) and Flowerhorn Cichlid (7.4–8) do not overlap, making it impossible to satisfy both species simultaneously.

For general hardness, the shared comfort zone is 9–10 dGH. Regular testing will ensure conditions stay within this range.

To house Apistogramma Marmor (Marbled Apisto) and Flowerhorn Cichlid 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: Sand (Sifters), Leaf Litter/Blackwater, Driftwood (Digestion/Hiding), Smooth Gravel (Sensitive Barbels). 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.

Apistogramma Marmor (Marbled Apisto) and Flowerhorn Cichlid 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.