PIctus catfish is a scavenger fish which cleans the aquarium eating away algae as it gets formed. Those who have aquariums know how difficult it is to keep it clean and they often have to empty it in order to clean it.
Scavenger fish saves the owner of an aquarium the time and energy that is required to keep an aquariu clean
There is a huge list of scavenger fish one can choose from but the Pictus catfish is mostly recommended.
This link has all the details
Do you have an aquarium?