Muriatic Acid is for use in swimming pools, concrete surfaces, and masonry surfaces. For concrete or masonry sufaces use at a rate of a 1/2 pint of Muriatic Acid per gallon of water. Let stand roughly 5 minutes then thoroughly rinse with sufficient amount of water. For pH in swimming pools if pH is above 8 use at a rate of 1 pint per 10,000 gallons of water. Let circulate for at least 2 hours then recheck to see if balance has been corrected.