The Mag-Float floating algae magnets. Remove algae from your aquarium without getting your hands wet. Super handy floating cleaner, cleans aquarium glass and floats to the surface when the inner magnet separates from the outer magnet. The Mag-Float's powerful magnets ensure a lifetime of durability and enough power to get the job done. Simply move the magnet on the outside, and the inside abrasive velcro magnet scrubber according to the glass. When the magnets are separated, the inner magnet floats back to the surface. This also prevents the magnet from picking up dirt from the bottom and the risk of scratching the aquarium glass.