Calcium Saturation Index is a method of determining whether your pool's water is "Corrosive", "Balanced" or "Scale Forming".  The Calcium Saturation Index incorporates the five balance factors: pH, Total Alkalinity, Calcium Hardness, Temperature and Total Dissolved Solids.  If the pool's water is not balanced according to the Calcium Saturation Index, chemicals will become less effective (i.e. Chlorine won't kill contaminants in the water) and damage to the pool's surface, plumbing and heater will result.  By maintaining your pool water in accordance with the Calcium Saturation Index, we will reduce the formation of scale, keep swimmers safe and prolong the life of your pool equipment.