Spa 56 Chlorinating Granules. Specifically formulated for spas, this concentrated granular chlorine effectively sanitizes and disinfects hot water. Features: Maintains clean, clear, sanitized water EPA approved Applications: Start-Up: Add 1/2 oz. of this product per 500 gallons of water prior to entering spa. Wait 5 minutes then check chlorine residual. Residual chlorine must read between 2 and 3 ppm. If it does not, additional dosages of material should be added until it does. Once the chlorine residual is established in the 2 to 3 ppm range, the spa or hot tub may be entered. Maintain: This product should be added daily or as necessary to maintain 2 to 3 ppm residual chlorine. Frequent checks should be made of residual chlorine using a reliable test kit. This product should be broadcast over the surface of the water and allowed at least 5 minutes mix time before testing. Note: Heavy bather usage or the use of oils or lotions may increase the chlorine demand resulting in the need for more frequent checks of chlorine residual. pH should be monitored with a reliable test kit and maintained at 7.2 to 7.8 for clean water. pH can be decreased by adding a suitable agent such as sodium bisulfate or increased by adding Aklalinity Up. Superchlorination: It is good practice to superchlorinate every 2 to 4 weeks. To superchlorinate, add 1 oz. of this product for each 500 gallons of water. Thoroughly clean spa, vacuum and cycle through filter. Resume program when chlorine residual reads 2 to 3 ppm. Compatible With: Chlorine sanitizing systems.