Use this Pool Mate 1 qt. Spa pH Up for Swimming Pools to raise the pH level of your spa water. Your spa or hot tub water should be maintained at a pH of 7.2 - 7.8. Test your water frequently with a test kit or test strip to ensure its pH levels remain in the recommended range. This pH increaser is compatible with all sanitizers including bromine, chlorine, and biguanide. This one quart bottle is available in select quantities.