Can Emerald Eye Rasbora and Pink Tailed Chalceus Live Together?

Emerald Eye Rasbora is a peaceful species (1/10), while Pink Tailed Chalceus is moderately assertive (6/10). This notable difference means Pink Tailed Chalceus may occasionally assert dominance over Emerald Eye Rasbora.

Emerald Eye Rasbora and Pink Tailed Chalceus both frequent the Top (Surface) region of the setup. This overlap can increase competition for space, so providing ample room and cover is important to keep both species comfortable.

There is a critical concern: the Nano / Bite-sized (Predation Risk) behaviour of one fish directly conflicts with the Piscivore (Eats small/nano fish) trait of the other — piscivorous fish will prey on nano-sized tank mates..

Additional behavioural considerations to keep in mind: Hyperactive swimmers can stress shy, slow-moving species through constant motion. Shrimp eaters may also prey on very small nano fish.

Worth noting: Pink Tailed Chalceus is a known jumper, so a tight-fitting lid is essential.

The safe temperature window for both species falls between 23°C and 26°C. Aim for the midpoint of this range (around 24.5°C) for optimal comfort.

Both fish can tolerate a pH between 6 and 7.5. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 5–10 dGH. Regular testing will ensure conditions stay within this range.

To house Emerald Eye Rasbora and Pink Tailed Chalceus together, plan for an aquarium of at least 250 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, Leaf Litter/Blackwater, Driftwood (Digestion/Hiding), Plants - Floating. Meeting these requirements will help both species thrive.

Emerald Eye Rasbora prefers Low (Still Water) flow while Pink Tailed Chalceus needs High (River/Stream) flow. Consider positioning filter outlets and using baffles to create zones of different current intensity within the same tank.

Emerald Eye Rasbora and Pink Tailed Chalceus 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.

Feeding time deserves special attention with this pairing. Pink Tailed Chalceus is a known shrimp eater and may prey on small invertebrates or nano fish like Emerald Eye Rasbora.