Are you still planning on doing a 10 gallon tank, or are you going to do a 20 gallon. I know earlier you mentioned about looking into the larger tank. With a 10 gallon tank you could do a single bristlenose pleco. With a 20 gallon tank you could do a rubber lipped (bulldog) pleco. One of the things to keep in mind is that with plecos they will produce a heavy bioload. Also some will eat certain types of algae when they are younger, but as they get older they will not eat algae as much and you need to make sure to supplement their diet, with algae waffers, fresh veggies and such.