Langelier Index

Langelier Index calculator (online calculator)

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

Give the values of your water analysis. All the fields with * are required.

Water Temperature (Fahrenheit or Celcius) ºF ºC
TDS (mg/L):
Ca (mg/L): 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 Recommended
4 Severe Scale Forming Treatment Recommended
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Please Note- SI Index is not a reliable means of evaluating corrosion potential, but it can be used as a guide.

  • Clean Water Systems & Stores, Inc., Water Treatment Equipment,Service & Supplies, Santa Cruz, CA