Calculate your pool's Langelier Saturation Index (SI) using this simple and user-friendly app. The Saturation Index will help you determine whether or not your pool chemistry is balanced, the first step in troubleshooting problems such as cloudy water, etc. All you have to do is input your pool's pH, water temperature, total alkalinity, calcium hardness, and total dissolved solids (TDS less than 1000 or greater than or equal to 1000) and we will tell you how balanced your water is along with a recommendation of the effects this may have on your pool equipment.