Pool Langelier Saturation Index (LSI) Calculator
Enter measured water values to calculate an approximate Langelier Saturation Index with the factor table in Pentair IntelliChlor Plus/LT P/N 523854 Rev B, printed page 9. The tool uses the nearest printed factor rows and corrects alkalinity by subtracting one third of measured CYA. It does not interpolate between rows or calculate chemical additions.
If borates are used or their use is uncertain, this table method is held because borate alkalinity is not corrected. Review the cited Pentair manual and test results before interpreting the number.
Check your measurements
Interpret LSI with your full water test
Consider the individual measurements as well as the calculated index. A balanced-looking result can coexist with an unsuitable sanitizer level or another water-quality problem; follow the calculator’s stated assumptions and limits.
Langelier Saturation Index (LSI)
Calculate an approximate water saturation index from measured chemistry and temperature using the cited Pentair table.
Pentair IntelliChlor Plus/LT P/N 523854 Rev B, printed page 9 table method. Nearest printed factor rows; no interpolation or chemical dose. Borate use is held. Read source guide.
