Cleaning up after a messy oscar

[NW Cichlid Keith]

Don't do a pleco, unless you really want and live plecos - and then still don't do it, unless it is a small species. They are poop machines, and their poop doesn't break down like others. I would suggest a featherfin squeaker synodontis catfish

 

[BIG-G]

One thing to think about whatever you choose if you go with a catfish species make sure its large enough that the oscar is not tempted to make a meal out of it. I have seen and heard of a lot of Oscars choked to death on small catfish.
They take them in only to get hung up by the spines and they can't swallow or spit them out and both of them end up dead.