LSI (Langelier Saturation Index) calculator
PROLangelier Saturation Index — target between -0.3 and +0.3.
Short answer: LSI = pH + TF + CF + AF − TDS constant. pH 7.5, 78°F, CH 250, TA 100, TDS 1000 → LSI ≈ 0.0 (balanced). Enter your measurements above and the lsi (langelier saturation index) calculator returns the quantity, unit conversions and an estimated cost instantly, in imperial or metric — no sign-up needed.
What do you need to measure?
What is the answer?
LSI
-0.19
Balanced
How does the lsi (langelier saturation index) calculator work?
LSI = pH + TF + CF + AF − TDS constant.
What does a worked example look like?
pH 7.5, 78°F, CH 250, TA 100, TDS 1000 → LSI ≈ 0.0 (balanced).
What do people ask most?
›Target range?
-0.3 to +0.3. Below = corrosive; above = scale forming.
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Where can you learn more?
Read field notes on estimating and materials, or browse every calculator we make.