Raises pH to ideal levels in your spa or hot tub. Balanced water chemistry is the first, most important step to clean, sparkling water in your spa or hot tub. Generally pH levels below 7.2 ppm can cause eye irritation, rapid use of spa chlorine or spa bromine, and corrosion. Use Spa Up in appropriate dosages to raise the pH in your spa or hot tub water to the ideal recommended range of 7.2 to 7.6 ppm (parts per million).