What is Langelier Saturation?

The Langelier Saturation Index (LI), a measure of a solution’s ability to dissolve or deposit calcium carbonate, is often used as an indicator of the corrosivity of water. The Langelier Index is defined as the difference between actual pH (measured) and calculated pHs.

What is the Langelier Saturation Index for water?

The Langelier Index is an approximate measure of the saturation degree of calcium carbonate (CaCO3) in water. It is calculated using the Hydrogen Ion (pH) , Alkalinity (CaCO3), Calcium concentration, Total Dissolved Solids, and water temperature of a tap water sample.

What does a negative Langelier index mean?

calcium carbonate
The Langelier Index is an approximate indicator of the degree of saturation of calcium carbonate in water. Langelier Index is negative, then the water is under saturated with calcium carbonate and will tend to be corrosive in the distribution system.

What is saturation index?

Saturation Index is a tool for determining if your pool’s water is corrosive or scaling. If your water is corrosive, the pool’s water will dissolve calcium in pool linings and protective coatings. If your water is scaling, calcium will be deposited on pipelines, filters, valves, and pump.

What is saturated pH?

The Langelier saturation level approaches the concept of saturation using pH as a main variable. The LSI can be interpreted as the pH change required to bring water to equilibrium. Water with a Langelier saturation index of 1.0 is one pH unit above saturation.

What is LSI in a pool?

The Langelier Saturation Index (LSI) is a cornerstone of the Orenda program. The LSI is the unbiased measurement of water balance, as defined by calcium carbonate saturation. It determines if our water is aggressive/corrosive (low LSI), balanced, or scale-forming (high LSI).

How can I increase my LSI?

Add sodium bicarbonate or baking soda to increase the Alkalinity and LSI value.

How do I find my Langelier index?

LSI Formula:

1. LSI = pH – pHs
2. pHs = (9.3 + A + B) – (C + D) where: A = (Log10[TDS] – 1)/10 = 0.15. B = -13.12 x Log10(oC + 273) + 34.55 = 2.09 at 25°C and 1.09 at 82°C. C = Log10[Ca2+ as CaCO3] – 0.4 = 1.78. D = Log10[alkalinity as CaCO3] = 1.53.

How do I calculate saturation?

Saturation is calculated using something similar to: S = [(MaxColor – MinColor) / (MaxColor + MinColor)] (with a 255 ceiling limit) where MaxColor is the highest value of (R, G, B) and MinColor is the lowest of (R, G, B).

How do you lower saturation index?

To lower your LSI value, add muriatic acid (can be found in pool supply stores). Consult the calculator above to determine the target pH value (recommended range is 7.2 to 7.6).

How do I test my pool LSI?

If CYA is in the pool, we must correct Total Alkalinity (TA) into Carbonate Alkalinity. This is because CYA contributes to TA as cyanurate alkalinity. To calculate the LSI, we must subtract Cyanurate Alkalinity from Total Alkalinity. Then use the Carbonate Alkalinity number for the alkalinity value in the table.

How do you increase LSI in water?

To raise your LSI value, add sodium bicarbonate or baking soda (can be found in pool supply stores). Consult the calculator above to determine the target Alkalinity value (recommended range is 80-120ppm; however, you may find that a level lower than 80 may be ideal for a balanced LSI value).