Can Aequidens diadema (Diadem Cichlid) and Electric Blue Johannii Live Together?

Aequidens diadema (Diadem Cichlid) is a moderately assertive species (6/10), while Electric Blue Johannii is semi-aggressive (8/10). This modest difference means Electric Blue Johannii may occasionally assert dominance over Aequidens diadema (Diadem Cichlid).

Aequidens diadema (Diadem Cichlid) and Electric Blue Johannii both frequent the Middle (Open Water) and 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 24°C and 28°C. Aim for the midpoint of this range (around 26.0°C) for optimal comfort.

The pH requirements of Aequidens diadema (Diadem Cichlid) (6–7.5) and Electric Blue Johannii (7.8–8.6) 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 Aequidens diadema (Diadem Cichlid) and Electric Blue Johannii together, plan for an aquarium of at least 295 litres with a minimum length of 90 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), 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.