The algae problem that you having could be caused by over feeding. How often do you feed your tank/live stock? If your feeding to much, what will happen is the uneaten food and waste will turn into ammonia. If you have a good biological filter system, that will turn ammonia into nitrite and then hopefully into nitrate. Algae feeds on nitrates. You should look into getting some kind of macroalgae to " eat " the nitrates. Or do water changes more often. Before you do anything, get your water tested.