In The Swim Pool pH Reducer 15 lb. Pail
This granular pH reducer is safer and easier to store than liquid muriatic acid.  Add pH Minus whenever the pH rises above 7.6.  Granular Sodium Bisulfate.  Initial Dosage: 15-30 oz. per 10,000 gallons.  10 lbs. pH Reducer is equivalent to 1 gallon of muriatic acid.