BioGuard Balance Pak 100 4# Item will ship USPS Priority Mail if ordered individually and ships same day, if not next day or order. Use Balance Pak 100 to maintain total alkalinity. Proper total alkalinity prevents pH from "bouncing" due to rain, bather load, and other chemical application. This helps prevent pool staining, plaster etching or liner wrinkling due to improper pH. Product Information: 100% sodium hydrogen carbonate pH 8.2 For raising total alkalinity Prevents pH change Improves swimmer comfort Prevents corrosion due to improper pH Protects vinyl liners from wrinkling due to improper pH Test and add Directions for use: 1. Add directly to your swimming pool with pump and filter running 2. 1.5 pounds of Balance Pak 100 per 10,000 gallons of water will raise your total alkalinity 10ppm 3. Large additions should be divided into thirds and added every 6 hours. Total alkalinity in your swimming pool water should be maintained in the range of 125-150ppm. For swimming pools using Mineral Springs or pools equipped with chlorine generators, total alkalinity should be 80-150ppm.