Do I need to feed otocinclus catfish?

[mkm0310]

Hello, if I have a healthy (too much!) Supply of green algae on rocks, etc., do I need to feel my otocinclus catfish algae wafers? I occasionally drop a small piece in but I'm not sure it's really necessary.

 

[Fresh2o]

Should not be necessary in a well established tank. They will feed on the algae and biofilm. However, they will accept vegetable based wafers.
I have a lone otocinclus (other died off years ago) and it will sometimes hang would with the Pygmy Corys at the bottom of the tank, especially at feeding time.