Clean the algae off the sides of your Desktop Jellyfish Tank without even getting your hands wet! Put the smaller side of the Algae Cleaner inside the tank and the larger side on the outside of the tank. Magnets in both pieces will hold them together on either side of the aquarium. Move the algae cleaner in circles to wipe off the algae. Be carful no sharp objects like pebbles get stuck between the algae cleaner magnet and plastic tank face as you do this because they can scratch the plastic.