Spa Frog Serene Cartridge Kit by King Technology

Refill Kit for the Spa Frog Mineral Purifier System. Kit Contains 3 Bromine Cartridges and 1 Mineral Cartridge. SPA FROG Mineral Products control bacteria and help keep the pH neutral, which reduces your chlorine or bromine use up to 50% (compared to the minimum ANSI recommended chlorine level of 2.0 ppm for a residential hot tub) and makes the water feel silky soft and look crystal clear.