Can Cardinal Shrimp (Sulawesi) and Mountain Rainbowfish Live Together?

Cardinal Shrimp (Sulawesi) is a peaceful species (0/10), while Mountain Rainbowfish is peaceful (2/10). This modest difference means Mountain Rainbowfish may occasionally assert dominance over Cardinal Shrimp (Sulawesi).

In terms of spatial distribution, Cardinal Shrimp (Sulawesi) prefers the Bottom (Substrate) zone, whereas Mountain Rainbowfish 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.

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

Worth noting: Mountain Rainbowfish is a known jumper, so a tight-fitting lid is essential.

There is no temperature overlap between Cardinal Shrimp (Sulawesi) (26–30°C) and Mountain Rainbowfish (17–24°C). This fundamental mismatch makes long-term cohabitation impractical.

Both fish can tolerate a pH between 7.5 and 8.5. Maintaining a stable value within this band is more important than hitting an exact number.

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

To house Cardinal Shrimp (Sulawesi) and Mountain Rainbowfish together, plan for an aquarium of at least 110 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: Established Algae (Otocinclus), Smooth Gravel (Sensitive Barbels), Sand (Sifters), Driftwood (Digestion/Hiding). Meeting these requirements will help both species thrive.

Cardinal Shrimp (Sulawesi) prefers Low (Still Water) flow while Mountain Rainbowfish needs High (River/Stream) flow. Consider positioning filter outlets and using baffles to create zones of different current intensity within the same tank.

Cardinal Shrimp (Sulawesi) and Mountain Rainbowfish 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.