We struggled to balance our hot tub water for nearly two years until we found this. We used the Aero Spa for a few weeks with far less need for sanitizers and then thought we'd stop using it to see if it was making a difference. Within two days of NOT using it, our water deteriorated. We still need to use chlorine (allergic to Bromine, bleach) but such small quantities that our water has no chemical smell. A huge thank you to Nick who helped us through this whole process -- the customer service level is extraordinary.