Freshwater "clean up crew"?

Hi all!

I'm wondering who I can "employ" to cleanup uneaten fish food, random algae, and all of that stuff that collects in the corners. I do water changes and vacuum, and have a fairly well planted tank, but I think it'll be neat to have some sort of a cycle in my tank.

I've heard that rubber mouthed plecos, cherry shrimp and snails were usefull, but I'm not sure I have enough (haha!) algae to feed even one pleco!

I have a 12 gallon tank, so I think plecos might be out (by the 1 inch per gallon rule, a 5 inch rubber mouthed pleco would already cramp up with my seven white clouds. There aren't any other fish in the tank.).