Can Bladder Snail (Pest Snail) and Japanese Ricefish (Medaka) Live Together?

Bladder Snail (Pest Snail) is a peaceful species (0/10), while Japanese Ricefish (Medaka) is peaceful (2/10). This modest difference means Japanese Ricefish (Medaka) may occasionally assert dominance over Bladder Snail (Pest Snail).

Bladder Snail (Pest Snail) and Japanese Ricefish (Medaka) 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.

Worth noting: Japanese Ricefish (Medaka) is a known jumper, so a tight-fitting lid is essential.

The safe temperature window for both species falls between 10°C and 28°C. Aim for the midpoint of this range (around 19.0°C) for optimal comfort.

Both fish can tolerate a pH between 6.5 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 5–20 dGH. Regular testing will ensure conditions stay within this range. An aquarium test kit is recommended for monitoring.

To house Bladder Snail (Pest Snail) and Japanese Ricefish (Medaka) together, plan for an aquarium of at least 23 litres with a minimum length of 30 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: Established Algae (Otocinclus), Plants - Densely covered, Plants - Floating. 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.