Formula “O” offers a simple, once a week additive to the water that will complete the treatment of your pool water. It simplifies treatment by combining numerous ancillary chemicals into one easy weekly application. The blend includes an activated oxygen shock along with other additives that prevent cloudiness, stains and other common problems. No extended waiting is required to use the pool after adding Formula “O”. Swimmers can re-enter the pool after 15 minutes. The addition of Formula “O” shocks the pool water to burn off additional contaminants deposited in the water through rains, winds and organic bather waste. Formula “O” is a nonchlorine, blended powder that is added to the water weekly. Formula “O” combines all of the typical ancillary chemicals (shock, clarifier, stain and scale prevention) into one easy weekly treatment.