What is the Saturation Index Value for a pool with pH = 7.3, Temperature = 67, Calcium Hardness = 250, Total Alkalinity = 100, and TDS = 1500?

To determine the Saturation Index Value (SIV) for a pool, the formula utilized is:

Saturation Index (SI) = pH + TF + CF - AF - 12.1

Where:

• pH is the pool's pH level.

• TF (Temperature Factor) depends on the temperature of the water.

• CF (Calcium Hardness Factor) is derived from the calcium hardness level.

• AF (Alkalinity Factor) is determined by total alkalinity.

In this calculation, first, the temperature factor (TF) is assessed based on a temperature of 67°F. Typically, for temperatures around 67°F, the TF is usually around 0.36.

Next, the calcium hardness factor (CF) is derived from the calcium hardness value given. For a hardness of 250 ppm, the CF is normally between 0.0 and 0.4, depending on the specifics of the hardness scale, with 250 often reaching a value of about 0.1.

Also, the alkalinity factor (AF) can be approximated from the total alkalinity, which here is 100 ppm. Using a common standard, an alkalinity of around 100 generally yields an AF of