Pool Water Balance Calculator

How It Works

The Langelier Saturation Index (LSI) tells you whether your pool water is balanced, corrosive, or scale-forming. It considers five factors: pH, temperature, alkalinity, calcium hardness, and total dissolved solids. An LSI between -0.3 and +0.3 is considered balanced. Below -0.3, water is corrosive and will attack metal fixtures, heater elements, and plaster surfaces. Above +0.3, water is supersaturated with calcium and will deposit scale on everything. Check your LSI monthly, especially after adding chemicals or changing water temperature. Balanced water protects your investment and keeps swimmers comfortable.