In Store Only Raises Alkalinity and helps control pH. To achieve maximum sanitizer efficiency and avoid pH variations, your spa water total alkalinity should be balanced. Maintaining a balanced alkalinity will ensure better bather’s comfort and protect your spa equipment. Directions for use: Check total alkalinity using a testing kit. The ideal recommended alkalinity level is 80-120 ppm with chlorine used as sanitizer and 100-150 ppm with bromine. To increase total alkalinity by 10 ppm, dissolve in a bucket of water 16g of Alkalinity per 1,000L of spa water. Add to the spa water. Check alkalinity levels regularly and make necessary adjustments.