Can Aequidens diadema (Diadem Cichlid) and Long-Finned African Tetra Live Together?

Aequidens diadema (Diadem Cichlid) is a moderately assertive species (6/10), while Long-Finned African Tetra is peaceful (2/10). This notable difference means Aequidens diadema (Diadem Cichlid) may occasionally assert dominance over Long-Finned African Tetra.

Aequidens diadema (Diadem Cichlid) and Long-Finned African Tetra 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: Long-Finned African Tetra 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 Aequidens diadema (Diadem Cichlid) and Long-Finned African Tetra 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 23°C and 26°C. Aim for the midpoint of this range (around 24.5°C) for optimal comfort.

Both fish can tolerate a pH between 6 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 5–15 dGH. Regular testing will ensure conditions stay within this range.

To house Aequidens diadema (Diadem Cichlid) and Long-Finned African Tetra together, plan for an aquarium of at least 200 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.

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: Sand (Sifters), Driftwood (Digestion/Hiding). Meeting these requirements will help both species thrive.

Aequidens diadema (Diadem Cichlid) prefers Low (Still Water) flow while Long-Finned African Tetra needs High (River/Stream) flow. Consider positioning filter outlets and using baffles to create zones of different current intensity within the same tank.