algae eaters

i have brown algae on my plants (fake), i have green algae on tiny bits of my glass. i don't have much luck with otos......they never cleaned up a bloody thing while they were alive. common garden variety pleco is a poo machine & he never really did a good job of cleaning either.

what can i get?

20 gallon - 2 platys, 2 balloon mollies, 2 adf's, 2 corys & 2 very small angels {& yes i know they will get to big for the tank }