HOW TO USE: Add the recommended amount of this product during evening hours while the filter pump is running. Broadcast the product evenly over a wide area in the deepest part of the poolMETHOD OF APPLICATION:For best product performance, swimmer comfort and crystal clear water, maintain the following daily levels as determined by a reliable testing kit. Use the appropriate pool care products to make adjustments.- Free available chlorine (FAC): 1.0-3.0ppm- pH: 7.2-7.8- Total alkalinity: 80-120ppm- Calcium hardness: 200-300ppmInitial shock treatment: When opening your pool, initially superchlorinate pool water with 150g of this product per 10,000L of pool water. For best results, superchlorinate at dusk.Routine chlorination: Maintain proper chlorine residual by broadcasting daily over the pool's surface, 30g of this product per 10,000L of pool water, or as needed.Note: Hot weather, heavy pool usage, and rain my require higher usage rates to maintain proper chlorine residual. For outdoor pools, chlorine residuals can be protected from destruction by run's rays by addition of stabilizer (cyanuric acid).