The ChlorEase Ultra produces chlorine right in the pool-automatically and continuously! You will love the soft water feel! With an initial dose of salt into the pool water(3,600-4,000 ppm), ChlorEase continually produces chlorine right in the pool. The ChlorEase can be used with all chemicals that are normally used in chlorine-maintained pools. The unit easily installs beneath the top rail of your pool and hangs down along the inner wall pool with no plumbing required. Simply plug the unit into a 110v GFI-protected outlet and start producing chlorine right away! Treats aboveground pools up to 18,000 gallons.