Can Molly (Sailfin/Black/Dalmatian) and Pike Cichlid (Xingu) Live Together?

Molly (Sailfin/Black/Dalmatian) is a generally mild-mannered species (3/10), while Pike Cichlid (Xingu) is highly aggressive (9/10). This notable difference means Pike Cichlid (Xingu) may occasionally assert dominance over Molly (Sailfin/Black/Dalmatian).

Large aggression gap (6 points) between Molly (Sailfin/Black/Dalmatian) and Pike Cichlid (Xingu) increases stress risk for the more peaceful fish.

Molly (Sailfin/Black/Dalmatian) and Pike Cichlid (Xingu) 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.

Worth noting: Pike Cichlid (Xingu) is a known jumper, so a tight-fitting lid is essential.

To improve the chances of a peaceful coexistence in this community tank: Provide a significantly larger tank (at least 50% more volume than the minimum) to allow both Molly (Sailfin/Black/Dalmatian) and Pike Cichlid (Xingu) to establish separate territories. Add plenty of line-of-sight breaks using driftwood, rocks, and dense planting to reduce territorial confrontations. A larger aquarium with ample hiding spots can help diffuse aggression and give the less dominant fish space to retreat.

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.

Both fish can tolerate a pH between 7.5 and 7.5. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 12–12 dGH. Regular testing will ensure conditions stay within this range.

To house Molly (Sailfin/Black/Dalmatian) and Pike Cichlid (Xingu) together, plan for an aquarium of at least 560 litres with a minimum length of 180 cm. This recommendation combines the stricter species minimums with a community-load allowance so the pairing has realistic long-term space and filtration headroom.

Because this pairing requires extra vigilance, include plenty of hiding spots — caves, driftwood, and dense plant clusters — so the less dominant fish can retreat when needed.

Specific environmental needs for this combination include: Plants - Densely covered, Established Algae (Otocinclus), Sand (Sifters), Driftwood (Digestion/Hiding), Smooth Gravel (Sensitive Barbels). Meeting these requirements will help both species thrive.

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

This pairing usually fails when the tank is treated like a standard mixed community and the caution flags are ignored. Molly (Sailfin/Black/Dalmatian) and Pike Cichlid (Xingu) need extra room, more cover, and closer observation during the first few weeks so small aggression, feeding, or territory issues do not snowball into a long-term problem.