Can Beckford's Pencilfish and Demasoni Cichlid (Mbuna) Live Together?

Beckford's Pencilfish is a peaceful species (2/10), while Demasoni Cichlid (Mbuna) is highly aggressive (9/10). This notable difference means Demasoni Cichlid (Mbuna) may occasionally assert dominance over Beckford's Pencilfish.

Large aggression gap (7 points) between Beckford's Pencilfish and Demasoni Cichlid (Mbuna) increases stress risk for the more peaceful fish.

Beckford's Pencilfish and Demasoni Cichlid (Mbuna) 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.

Additional behavioural considerations to keep in mind: Aggressive fish may bully and stress shy, slow-moving species. Hyperactive swimmers can stress shy, slow-moving species through constant motion.

Worth noting: Beckford's Pencilfish is a known jumper, so a tight-fitting lid is essential.

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 Beckford's Pencilfish (5–7.5) and Demasoni Cichlid (Mbuna) (7.6–8.6) 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. An aquarium test kit is recommended for monitoring.

To house Beckford's Pencilfish and Demasoni Cichlid (Mbuna) together, plan for an aquarium of at least 240 litres with a minimum length of 120 cm. This accounts for the larger species' space requirements with an additional 20 % buffer to reduce territorial tension.

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: Plants - Densely covered, Plants - Floating, Leaf Litter/Blackwater, Sand (Sifters), Established Algae (Otocinclus). Meeting these requirements will help both species thrive.

Note a potential conflict in setup requirements: Demasoni Cichlid (Mbuna) is a plant destroyer, which conflicts with Beckford's Pencilfish's requirement for live plants. Compromise where possible or prioritise the more critical need.

Beckford's Pencilfish prefers Low (Still Water) flow while Demasoni Cichlid (Mbuna) needs High (River/Stream) flow. Consider positioning filter outlets and using baffles to create zones of different current intensity within the same tank.