Start the treatment in the early evening. Clear the weir and pump baskets of debris. Backwash the filter for 3 minutes then rinse for 2 minutes. With the pump on the filter position, sprinkle contents of pack 1 around the sides of the pool then sprinkle contents of pack 2 around the sides of the pool. Allow to filter for 12 hours. Once the 12 hours filtering is complete, clear the pump and weir baskets of debris. Backwash for 3 minutes, then rinse for 2 minutes. Continue filtering for a further 12 hours.