Actually, the HotSpring tubs come standard with a very good Ozone injection system. Put that together with the great filtration, and a Nature2 Silver Ion Cartridge and you can soak chlorine free without having to use Baqua or other alternative sanitizers. Yes, you will need to do a chlorine shock once a month or after a crowd exits the spa, but that chlorine leaves the water rather quickly leaving you to soak chlorine free for the rest of the time.