The Langlier Index

 
Temp deg F = TV Calcium Hardness = HV Total Alkalinity = AV
32° = 0.0 5 = 0.3 5 = 0.7
37° = 0.1 25 = 1.0 25 = 1.4
46° = 0.2 50 = 1.3 50 = 1.7
53° = 0.3 75 = 1.5 75 = 1.9
60° = 0.4 100 = 1.6 100 = 2.0
66° = 0.5 150 = 1.8 150 = 2.2
76° = 0.6 200 = 1.9 200 = 2.3
84° = 0.7 300 = 2.1 300 = 2.5
94° = 0.8 400 = 2.2 400 = 2.6
105° = 0.9 800 = 2.5 800 = 2.9
128° = 1.0 1000 = 2.0 1000 = 3.0
pH ___ + TV ___ + HV ___ + AV ___ -- 12.1 = Langlier Index

If Index is between -0.5 and +0.5 the water is Balanced

If Index is less than -0.5 the water is Corrosive

If Index is greater than +0.5 the water is Scale Forming


Fill in the form below to calculate your Langelier Index

Total Alkalinity: 
Calcium Hardness: 
Temp. (°F): 
Measured pH: 
Langelier Saturation Index: