Langlier Calulator: Calculating the Langelier Saturation Index or LSI

Calculators for Water Treatment
Diagrams & Schematics
Frequently Asked Questions
Glossary of Water Terms
How-To-Guides
Manuals & Installation Guides
System Selector Wizards
Water Sources

Technical Resources >> Calculators for Water Treatment >> LangelierSaturation Index Calculator

LangelierSaturation Index Calculator

This calculator helps you determine the scaling potential of the water by using the Langelier Saturation Index

To use the Langelier Saturation Index Calculator, simply enter your values for pH, Temperature (in Celcius or Fahrenheit), TDS (mg/L), Ca, and Alkalinity (as CaCO₃) in the boxes below and then click on the "Calculate Now" button.

Temperature (Fahrenheit or Celcius):

*F *C

pH:

TDS (mg/L):

Ca (mg/L):

as CaCO₃ Ca²⁺

Alkalinity (mg/L as CaCO₃):

Langelier Index:

Saturation Index	Description	General Recommendation
- 5	Severe Corrosion	Treatment Recommended
- 3	Moderate Corrosion	Treatment Recommended
- 2	Moderate Corrosion	Treatment May Be Needed
- 1	Mild Corrosion	Treatment May Be Needed
- 0.5	None- Mild Corrosion	Probably No Treatment
0	Near Balanced	No Treatment
0.5	Some Faint Coating	Probably No Treatment
1	Mild Scale Coating	Treatment May Be Needed
2	Mild to Moderate Coatings	Treatment May Be Needed
3	Moderate Scale Forming	Treatment Advisable
4	Severe Scale Forming	Treatment Advisable

Please Note- SI Index is not a reliable means of evaluating corrosion potential, but it can be used as a guide.