Salt pools operate slightly differently than traditional chlorine pools. They're both sanitized using chlorine, but the chlorine in a salt pool is generated when salt is dissolved in water, rather than being directly added to the pool like in a chlorine pool.
Traditional chlorine pools typically have a chlorine level of 1-3 ppm (parts per million), while salt pools typically have a chlorine level of 1-3,500 ppm. Although saltwater's chlorine levels are higher, the chlorine itself is less harsh in salt water pools than in chlorine pools. The saltwater system generates a form of chlorine called hypochlorous acid, which is less reactive and dissipates more slowly than the chlorine in traditional chlorine pools. This slower dissipation means the salt pool doesn't require additional chlorine as frequently, and plants around the pool are less exposed to high levels of chlorine.