Here is an interesting discussion about salt water pools:
Everyone loves salt water pools, but they are not “Chemical Free” as claimed. Salt in water is corrosive (just like the ocean water) and makes keeping your pool’s pH low a bit of a challenge. Many pool owners are not willing to test the pH several times a week to keep it under 7.8.
Salt adds TDS to the pool water as well as iron.
If you do decide to go with a salt system, place a CuLator Metal Eliminator Ultra 4.0 in the pump basket every 4-6 months to bind the iron from the salt out of the water. That way, you will prevent metal stains even if the pH climbs up by using salt.