Can Clown loach Live With Coolie loach?

These two share a habit, not a scale. The clown loach's own profile says not to keep it with much smaller fishes, which may be intimidated by its size and sometimes very active behaviour, and a grown clown loach reaches 30 cm against the kuhli's slender 10. The same page names other loaches among workable bottom company, so this is a question of proportion rather than a flat prohibition, but it also notes that a clown loach kept without its own kind can turn on similarly shaped fish, and a kuhli is exactly that shape.

Water needs planning. The clown loach wants 24 to 30 °C and the kuhli 21 to 26, so the only shared ground is 24 to 26 °C, with pH 5.5 to 6.5 suiting both.

Both are group animals and both need the numbers: five or six kuhlis at minimum, and five or six clown loaches, preferably ten, since a lone clown loach becomes withdrawn or aggressive. That makes this a large tank question, as the clown loaches alone are measured for 250 litres. Fine sand and many separate caves matter more than usual, so the kuhlis have somewhere to pack into that the bigger fish have not already claimed, and feeding after lights out gives them a real share.