It is said to use Natural Enzymes.A ton of great reviews.I may try it.Just got our spa but I am already sick of maintaining it.Needing lots of chemicals and clarifier already.And I am having Foam issues.Granted we haven't seperated bathing suits washed detergent free yet.I am surprised nobody here has chimed in yet.I have to call my stepfather-he had a spa for ten years and said that he used "Natural" products,not chemicals.I am wondering if he was using something like this stuff.