Increase the total alkalinity of your swimming pool or hot tub water and prevent it from becoming corrosive Help control your water's alkalinity level, reduce the acidity level and maintain a correct PH Water that's too acidic can cause chlorine treatment not too work effectively leading to pool/hot tub damage and irritation Recommend using the alkalinity increaser if your water drops below 7.2 on the pH scale or below 80mg/L alkalinity level Clearwater is a BISHTA approved member and recommended by brands such as Bestway and Lay-Z-Spa for reliable, safe and high-quality water treatment