Can plecostomus fish clean the aquarium?

The plecostomus is an omnivorous fish and, strictly speaking, it does have some tank-cleaning ability. Young plecos like to eat algae, microorganisms, and even the waste of other fish in the tank. But once a pleco grows up, its cleaning effect drops; it competes with other fish for food, rarely eats algae, and may even bite other ornamental fish, then eat them after their wounds become infected and they die.

In addition, adult plecos produce a large amount of waste themselves, so they are also a major source of garbage and water-quality problems. Therefore, it is not recommended to use plecos to clean the aquarium.