Can Apistogramma Mouthbrooder (Maulbrüter) and Dusky Millions Fish Live Together?

Apistogramma Mouthbrooder (Maulbrüter) is a moderately assertive species (6/10), while Dusky Millions Fish is peaceful (2/10). This notable difference means Apistogramma Mouthbrooder (Maulbrüter) may occasionally assert dominance over Dusky Millions Fish.

Apistogramma Mouthbrooder (Maulbrüter) and Dusky Millions Fish 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.

The safe temperature window for both species falls between 24°C and 24°C. Aim for the midpoint of this range (around 24.0°C) for optimal comfort.

The pH requirements of Apistogramma Mouthbrooder (Maulbrüter) (4.5–6.8) and Dusky Millions Fish (7–8) do not overlap, making it impossible to satisfy both species simultaneously.

For general hardness, the shared comfort zone is 8–8 dGH. Regular testing will ensure conditions stay within this range.

To house Apistogramma Mouthbrooder (Maulbrüter) and Dusky Millions Fish together, plan for an aquarium of at least 65 litres with a minimum length of 60 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), Driftwood (Digestion/Hiding), Leaf Litter/Blackwater, Plants - Densely covered, Plants - Floating, Established Algae (Otocinclus). 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 Mouthbrooder (Maulbrüter) and Dusky Millions Fish 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.