ok, i am in desperate need of a good bottom feeder thats eats old food that sits on the bottom. i have a 20 gallon tank with not too many fish, just small ones, 2 small cory cats, khuli loach, and a pleco, the khuli goes to the top to eat, the pleco jsut eats the algea that grows, and the corys do nothing lol. anyone got any ideas of a good bottom feeder thats dependable??thanks!