The buoy uses solar technology and ionization to reduce the use of chlorine, chemicals, and eliminate as much algae and microorganisms as possible from the pool. It's 100% sustainable! The device floats in a pool of water and produces copper ions while being exposed to sunlight. In about a week, the ionizer effectively regulates the level of copper ions in the pool water, making maintenance very easy and reducing time, energy and money. It is important to note that your pool will still require chlorine and chemicals, but much less than without this ionizer. The copper electrode will last for about two years (depending on the hardness and chemical composition of the water)