Blue Horizons Rapid Shock Chlorine qucik action dose of chlorine, faster acting than the traditional granular shock. Key Features/Characteristics - Helps prevent/remove algae - Destroys swimmer wastes - Rapid Dissolving - pH 11.5 - Part of the BOAST System Application Instructions Maintain pH levels within the ideal range 7.2 7.6. If the level is not in this range, adjust. Maintain free chlorine residuals routinely in the 1 3mg/l (ppm) range. Shock or oxidising procedures are recommended either weekly or fortnightly with a maximum of 10mg/l (ppm) for a full shock treatment. If the water temperature is 20oC or higher and water depth at least 4ft deep, this product can be carefully broadcast directly over the pool surface. Always check the wind direction before broadcasting. Alternatively, pre-dissolve this product in a clean plastic container at a maximum rate of 100g of product of 2.2 gallon (10 litres) in water. Stir well to ensure product is fully dissolved. Add the r