Can bottom feeder fish clean sand?

Bottom feeder fish can help to keep sand clean by eating algae, detritus, and other organic matter that can accumulate on the bottom of an aquarium. This can help to prevent the sand from becoming compacted and anaerobic, which can create an unhealthy environment for fish and other aquatic life. Some species of bottom feeder fish that are particularly good at cleaning sand include corydoras catfish, kuhli loaches, and mollies.