Australian Innovative Systems - Water Balance (Langelier Saturation Index) Calculator

Water Balance (Langelier Saturation Index) Calculator

This calculator is designed to help you determine the Calcium Saturation Index of your pool. The benefit of having the Calcium Saturation Index of your pool water balanced, is cleaner water with more efficient chlorine production and greater equipment life.

The Calcium Saturation Index of your pool determines whether your water is corrosive, scale forming or balanced. If your water is in a corrosive state it will begin to saturate itself by dissolving the structure of your pool components including your chlorinators electrolytic cell. At the other extreme if it is scale forming it will try to correct its over saturation by precipitating the hard water salts causing cloudy water depositing scale on pool components including your electrolytic cell, which means a shorter time between cell cleaning.

For this reason a balanced CSI is an important consideration during your pool maintenance

How to calculate your CSI

Step One: Test your water for PH, Calcium Hardness, Total Alkalinity and Temperature
Step Two: Enter the values into the calculator provided to calculate your CSI value

If the CSI calculation is zero then the water is balanced. If the CSI value is less than 0 then the water will tend to be corrosive. If the CSI value is greater than 0, then it is said to be scale forming.

An acceptable range is -0.5 to +0.5. If the result is outside this range, adjustments should be made to the hardness, alkalinity and pH to bring it as close to zero as possible. Your local pool store should be able to help you with this.

Be aware however, that whilst the water may be balanced from a corrosion and scaling point of view it does not necessarily mean that it is ideal for sanitiser efficiency and bather comfort.