Can Dojo Loach (Weather Loach) and Harlequin Rasbora Live Together?

Dojo Loach (Weather Loach) is a peaceful species (2/10), while Harlequin Rasbora is peaceful (1/10). This modest difference means Dojo Loach (Weather Loach) may occasionally assert dominance over Harlequin Rasbora.

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

Worth noting: Dojo Loach (Weather Loach) is a known jumper, so a tight-fitting lid is essential.

The safe temperature window for both species falls between 22°C and 24°C. Aim for the midpoint of this range (around 23.0°C) for optimal comfort.

Both fish can tolerate a pH between 6.5 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 5–12 dGH. Regular testing will ensure conditions stay within this range.

To house Dojo Loach (Weather Loach) and Harlequin Rasbora together, plan for an aquarium of at least 200 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.

Because this pairing requires extra vigilance, include plenty of hiding spots — caves, driftwood, and dense plant clusters — so the less dominant fish can retreat when needed.

Specific environmental needs for this combination include: Sand (Sifters), Plants - Densely covered, Leaf Litter/Blackwater. Meeting these requirements will help both species thrive.

Note a potential conflict in setup requirements: Dojo Loach (Weather Loach) is a plant destroyer, which conflicts with Harlequin Rasbora's requirement for live plants. Compromise where possible or prioritise the more critical need.

Both species do well with moderate (standard) water movement, so a standard filtration setup rated for the tank volume should suffice.

This pairing usually fails when the tank is treated like a standard mixed community and the caution flags are ignored. Dojo Loach (Weather Loach) and Harlequin Rasbora need extra room, more cover, and closer observation during the first few weeks so small aggression, feeding, or territory issues do not snowball into a long-term problem.