Use Azure Quick Dissolving Shock weekly to Shock your Swimming Pool, and at the first signs of Algae, after heavy rainfall, or when your Swimming Pool has been used a lot. Mother nature affects the purity and clarity of your pool water. Wind and rain dump dirt, pollen and insects into your sparkling pool and swimmers introduce problems of their own - suntan lotion, make-up, dirt and perspiration. These contaminants can cause unpleasant Chlorine odors, eye irritation and cloudy water as well...