When pool water has low total alkalinity, it’s difficult to maintain the pH of the water in the proper rage of 7.2 – 7.6. This difficulty is commonly referred to as “pH bounce.” Low total alkalinity can cause pitting, etching and weakening of the plaster pool surfaces as well as corrosion of metal fixtures in the pool. Our Alkalinity Plus is a great remedy for this.  Sizes:  2 lb. canister and 22 lb. tub