On Feb 14, 7:44?am, "Pablo" wrote:
I have not checked the water chemistry, but it is clean, not debris,
and nearly odorless. I tried flakes, algae waffers, and a even
lettuce. He is always sucking or stuck to walls or the raiser tube. Is
he really eating algae even If I don't see them? It Seems healthy
since he moves around fast, but I am quite concerned....

Any clue?

In order to know what or if it's eating, you'll have to find out what
kind of Pleco it is. There are hundreds of types. Many are strict
vegie eaters, while many are omnivores.
What size tank is this and also, how long has it been set up and
running with fish?