Common Plecos and Clown Loaches will get way to large for a 10 gallon aquarium. If you want a pleco, go with a bristle nose pleco or a clown pleco, both species are relatively easy to find. Even those may get to large for a 10 gallon, max size is about 5 inches. What you may want to go with are a few ottos. Small algae eaters that are very similar to plecos.