Can Beckford's Pencilfish and Socolofi Cichlid (Pseudotropheus Socolofi) Live Together?

Beckford's Pencilfish is a peaceful species (2/10), while Socolofi Cichlid (Pseudotropheus Socolofi) is semi-aggressive (8/10). This notable difference means Socolofi Cichlid (Pseudotropheus Socolofi) may occasionally assert dominance over Beckford's Pencilfish.

Large aggression gap (6 points) between Beckford's Pencilfish and Socolofi Cichlid (Pseudotropheus Socolofi) increases stress risk for the more peaceful fish.

Beckford's Pencilfish and Socolofi Cichlid (Pseudotropheus Socolofi) 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 Socolofi Cichlid (Pseudotropheus Socolofi) (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.

To house Beckford's Pencilfish and Socolofi Cichlid (Pseudotropheus Socolofi) together, plan for an aquarium of at least 260 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.

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), Smooth Gravel (Sensitive Barbels). Meeting these requirements will help both species thrive.

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

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

Beckford's Pencilfish and Socolofi Cichlid (Pseudotropheus Socolofi) 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.