Stabilizer plays an important role in reducing the loss of chlorine to sunlight. An ideal level of 30-40ppm should be achieved. Stabilizer raises this level when low. This is the traditional, very slow dissolving, granular product. It can be applied slowly through the skimmer where it traps in the filter and slowly dissolves into the water. Ideal for use in any outdoor pool utilizing chlorine as sanitizer. This includes salt water pools.