Can Cardinal Shrimp (Sulawesi) and Dwarf Pencilfish Live Together?

Cardinal Shrimp (Sulawesi) is a peaceful species (0/10), while Dwarf Pencilfish is peaceful (1/10). This modest difference means Dwarf Pencilfish may occasionally assert dominance over Cardinal Shrimp (Sulawesi).

In terms of spatial distribution, Cardinal Shrimp (Sulawesi) prefers the Bottom (Substrate) zone, whereas Dwarf Pencilfish occupies the Top (Surface) and Middle (Open Water) zones. Because they use different levels of the water column, territorial disputes are less likely and the tank will appear more balanced.

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

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.

The pH requirements of Cardinal Shrimp (Sulawesi) (7.5–8.5) and Dwarf Pencilfish (4–7) do not overlap, making it impossible to satisfy both species simultaneously.

For general hardness, the shared comfort zone is 4–8 dGH. Regular testing will ensure conditions stay within this range.

To house Cardinal Shrimp (Sulawesi) and Dwarf Pencilfish together, plan for an aquarium of at least 40 litres with a minimum length of 45 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: Established Algae (Otocinclus), Smooth Gravel (Sensitive Barbels), Sand (Sifters), Plants - Densely covered, Plants - Floating, Leaf Litter/Blackwater. 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.

Cardinal Shrimp (Sulawesi) and Dwarf Pencilfish 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.