This magnetic scraper pad is a critical part of staying on top of the day to day fight against algae. Use this cleaner for just a few minutes every couple days to preemptively scrub algae before it becomes established. Do this, and you will never have to fight green dot algae which once established can be very difficult to control. Mag-Float scrubber prevents toxic lotions or soap residue on your skin from getting in your aquarium. This Mag Float For Glass is made with super strong magnets. Simply drag the no-scratch felt-lined mag float cleaning handle. Inside your tank the mag float scrubber follows, cleaning as it goes. If the magnets separate, the scrubber floats right back to the surface, so you'll never have to dig around on the bottom. It adheres to aquarium walls and scrapes away even tough algae stains, leaving tanks crystal clear! It can easily be guided around tank corners without sinking, so you never have to worry about getting wet while cleaning or gravel becoming lodged in the cleaner.