For the clearest, healthiest possible pool water you need the Pool Rx Mineral System. This is for pool owners who want to eliminate algae, lower chemical costs, and go natural. Simply place the small basket containing the mineral bag surrounded by the metal actuator tube in your skimmer basket and you're ready to reduce your chlorine usage to .5-1.0ppm or turn your salt system down by 50%. The drop-in basket design means there is no installation or any tools needed. Each unit lasts 6 months. The PoolRx Mineral unit can be placed in a skimmer or pump basket. The minerals automatically dissolve with normal water circulation and then take on an ionic charge as they pass through the metal cylinder. The copper, silver, and zinc work with a low level of chlorine as a dual disinfectant that is highly effective at eradicating existing algae and will maintain a superior sanitization level. The zinc naturally descales salt cells, extending their life, while preventing scaling of pool surfaces. Its performance is unaffected by sunlight or bather load and is only lost through backwash, splash out, and algae kill.