Liquid Spa Down is compatible with all sanitizers including bromine, chlorine and biguanide.Product Features:Lowers the pH level of your spa waterSpa water should be maintained at a pH level of 7.2 to 7.8Test water frequently with a test kit or test strip (not included) to ensure pH levels remain in the recommended rangeCompatible with all sanitizers including bromine, chlorine and biguanideInclud