Directions: Test your pool water. Per the manufacturer: in vinyl and fiberglass pools, total alkalinity levels should be between 125 – 150 ppm and in pools with plaster or similar surfaces, calcium hardness levels should be between 100 – 150 ppm. If your Total Alkalinity is low, determine the dosage needed to increase to the correct level. 1.5 lb per 10,000 gallons of pool water will increase your Total Alkalinity by 10 ppm. Broadcast across pool with pump running. Large dosages should be applied 1/3 per treatment with 3-5 hours to circulate between treatments. Hint: if pH and Total Alkalinity are low, start by raising your Total Alkalinity first.