Langelier Saturation Index

The best thing you can do for your hot tub is to make sure it is well balanced. Test your water and fill in the necessary measurements for your hot tub or hot tub water.

If the result is between -0.5 and 0.5 the water is balanced.

If it is below -0.5 or over 0.5 your water is either over or under saturated, which can lead to problems. Add the necessary adjustment products to bring your pH, Total Alkalinity (TA), and Calcium Hardness (CF) within the proper standards, then retest.

Ideal readings for proper water balance:

  • pH 7.2 to 7.8
  • Total Alkalinity 80 to 180 ppm (parts per million)
  • Calcium Hardness 150 to 400 ppm (parts per million)

Determine Your Water’s Saturation Index

Test the water for pH, Alkalinity, Calcium Hardness and Temperature.  Then, enter the information below.

In the next sections, we will discuss each individual component of water balance in detail. Click here for a printable copy of the Langelier Saturation Index table.