Increases chlorine effectiveness, with the addition of cyanuric acid, commonly called stabilizer. Prevents unnecessary loss of chlorine due to the sun. For outdoor pool use. When stabilizer levels are maintained, chlorine consumption is reduced. With a clean filter, water balanced and disinfectant level at least 3 ppm, add stabilizer. Stabilizer does not dissolve immediately. Many facilities use a sock and place securely in the balance tank to let it dissolve. Pre-mixing in a clean bucket and pouring around the perimeter of the pool can also be done to add the stabilizer. Ideal level is 20 to 30 ppm. 1 lb. of stabilizer will increase 10,000 gallons of water by 10 ppm. Can take up to three days for the cyanuric acid to dissolve and mix in the pool water. Those with automatic controllers will need to make adjustments for the change in the oxidation reduction potential. Additional size available: 50 lb. pail