Buy a long pair of forceps: http://www.drsfostersmith.com/produc...m?pcatid=12038 Cut a small 1/2 in X 1 in piece of soft sponge (without scrubber pad) and grasp it in the forceps. Wrap a plastic twist tie around the forceps to keep them gripping the sponge. Rub the algae off the sides of the tank. You could use the scrubber pad on a glass tank. These forceps are also great for planting in small spaces.
what i do on mine is drain the tank, and use a paper towel wet with peroxide to wipe down the inside lightly, you dont have to scratch. it w kill the growths on the glass and bleach it clear again nicely w no scrubbing