The Fluval Algae Magnet is specifically designed for Fluval EDGE aquariums. The Algae Magnet enables you to clean the inside of the aquarium's glass without getting your hands wet. Its slim design is ideal for hard to reach areas, such as beneath the gravel line, behind heaters, around rocks and decorations. A large internal scrubbing pad makes it easy to see what youre cleaning. The powerful magnets ensure a tight grip and the non-abrasive cleaning pads will not scratch the glass surface. It also has a specially-designed floating magnet retriever. The Algae Magnet is suitable for glass aquariums only, fresh or saltwater.