Always add with pump and filter running to ensure complete mixing and good circulation. Poolife Exclusive Pool Care Collections Quick Swim Oxidizer is completely soluble and dissolves quickly, so no premixing is required. Broadcast this product uniformly over the surface of the water, adding about two thirds of the total dose into the deep end of the pool. Apply product when swimming pool is not in use. Swimming may resume as soon as 15 minutes after product application, provided the chlorine residual concentration in the pool is between 1 and 4 ppm. Reentry is prohibited above levels of 4 ppm chlorine due to risk of bodily injury.