Kuhli loaches are social bottom-dwellers and are generally more confident in groups than alone. A group of around five or six is a sensible starting point, with larger groups possible in bigger tanks. Floor area, hiding places and access to sinking food matter more than tank height. Each loach should be able to retreat without the group competing for one cave.
Kuhli loaches are famous for disappearing. Some hiding is normal, but keeping one isolated loach in a bare tank can make that behaviour extreme. Social company and secure habitat work together.
Why groups help
Kuhli loaches often rest together and become bolder when several conspecifics are present. A group gives them social cues that a lone fish lacks.
Floor area matters
These fish use the substrate and lower hardscape, so a long footprint provides more useful habitat than extra height alone.
Provide multiple hides
The RSPCA notes that kuhli loaches need caves and hiding places. Use several secure refuges, plants and wood so the group can choose where to rest.
Feed for nocturnal behaviour
Sinking foods offered in several locations, especially near dusk or after lights dim, can help every loach get access without competing with faster daytime fish.
Related aquarium tools and guides
Frequently asked questions
Can I keep one kuhli loach?
It is better to keep a social group rather than a single isolated fish.
Is six kuhli loaches too many?
Not in a suitably sized aquarium with enough floor area and filtration.
Why do my kuhli loaches still hide in a group?
Hiding is normal, especially during the day, but adequate cover and a group often make them more confident.
Sources and further reading
This guide separates general aquarium arithmetic from fish-welfare decisions. For species-specific limits, always check the needs of the fish you intend to keep.