Can Betta (Siamese Fighting Fish) and Boeseman's Rainbowfish Live Together?

Betta (Siamese Fighting Fish) is a moderately assertive species (5/10), while Boeseman's Rainbowfish is peaceful (2/10). This modest difference means Betta (Siamese Fighting Fish) may occasionally assert dominance over Boeseman's Rainbowfish.

Betta (Siamese Fighting Fish) and Boeseman's Rainbowfish both frequent the Top (Surface) and 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.

Worth noting: Betta (Siamese Fighting Fish) is a known jumper, so a tight-fitting lid is essential.

The safe temperature window for both species falls between 26°C and 30°C. Aim for the midpoint of this range (around 28.0°C) for optimal comfort.

Both fish can tolerate a pH between 7 and 8. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 9–19 dGH. Regular testing will ensure conditions stay within this range.

To house Betta (Siamese Fighting Fish) and Boeseman's Rainbowfish 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, Smooth Gravel (Sensitive Barbels), Plants - lighly covered. 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.