Seriously though, you will have to try a pleco and see. Some JDs might kill them, some might ignore them. Try brisstlenoses as they get about the right size to not be considered a meal and they eat alot of algae. You might also want to try malaysian trumpet snails (if any snail can make it in a JD tank MTS can).
Look at cutting down your light cycle. If you have no live plants there is absolutley no reason to have the light on when your not sitting in front of the tank (ie turn it off while your at work).
Feed less / Water change more. The less you feed the less the fish poop, and the less phosphate and nitrate is in your water, the less algae you will get. Water changes take out nitrates and posphates and replace it with cleaner water.