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The Langlier's Saturation Index
Water chemistry plays an important role in the effectiveness of the Aquafer Water Source as it applies to preventing scale.
Remember, this is not a water softener, the calcium ions are not removed from the water (as is the case with a
The calcium ions are actually left in the water but they are precipitated into a solid particle which passes through
the plumbing system without leaving a scale behind. In order for this process to be effective, the raw (untreated) water must not exceed a certain limitation.
This limitation is measured by the Langlier's Saturation Index. The Langlier's Saturation Index is a calculated number used to predict the calcium carbonate (CaCO3) stability of
a water. That is, whether a water will precipitate, dissolve, or be in equilibrium with calcium carbonate.
We use the index to determine whether a water will be within the limits required for the effective application of
the Aquafer Water Source. Any index value that is equal to or less than 1.6 is considered favorable for achieving effective results with the
Aquafer Water Source.
Below is the process to determine a water's Saturation Index Value.
Computing a Langlier's Saturation Index
Value.
In order to calculate an index value, the water in question must be tested. We
need to know the Hardness, Alkalinity and pH of your water. To obtain this information
for City water systems, contact your municipality. They test the
water on a daily basis and should be able to give you the information
over the phone. Please write down the information and e-mail
it to us at customerservice@waraloninc.com. We
will answer you with a recommendation as to which system will work best for you.
If you are on a Well water system we
will test the water for you. This test is free to you! Here is all you
need to do. Place at least 1 oz of water from your tap into a clean container.
Label the container clearly with your name, address, phone number and e-mail
address. Mail to:
War-A-Lon, Inc.
PO Box 75
Rexford, MT 59930
We will e-mail you with the results
and recommendation within approximately 2 weeks of receipt of your water. Sooner
if at all possible. It is as easy at that!
How The Testing
Is Done:
Only 3 tests must be performed - these tests
are as follows:
1. Hardness Test.
2. Alkalinity Test.
3. pH test.
These 3 tests, along with factoring in the ambient water temperature, will derive an index value.
The formula for deriving the index value is as follows:
Saturation Index Value = pH + Hardness Factor + Alkalinity Factor + Temperature Factor - 12.1 (12.1 is a
constant in the formula)
A saturation index value of zero is perfectly balanced (non-corrosive & non-scaling).
A negative saturation index value will tend to be corrosive (the higher the negative value, the more corrosive potential of the water).
A positive saturation index value will tend to scale (the higher the positive value, the more scale potential of the water).
The Aquafer Water Source
or Maxicure
will render a positive index value water non-scaling up to a value of 1.6.
In order to generate the four input values to determine the index value, you must first test the hardness,
alkalinity, and pH levels of the water. This is done with the above mentioned test kits.
Once the levels are known, you must generate a factor for each tested level.
This is done by comparing the tested level to the factor chart below.
Langlier's Saturation Index Example:
For example - a hypothetical water sample tested as follows:
Hardness - 300 ppm or mg/l (parts per million or milligrams per liter)
Note: ppm and mg/l are units of measure used in testing water and are equal in measure.
Alkalinity - 150 ppm or mg/l
pH - 7.2
The average cold water temperature is 66 degrees
Fahrenheit and the hot water heater is set at 140ºF.
We then compare these values with the Factor Chart below to derive the factor values for the Saturation Index Formula.
-
- Total Hardness
|
Total
Alkalinity |
Temperature |
|
Tested Value - ppm |
Hardness Factor |
Tested Value - ppm |
Alkalinity Factor |
Degrees - Faranheit |
Temperature Factor |
|
5 |
0.3 |
5 |
0.7 |
32 |
0.1 |
|
25 |
1.0 |
25 |
1.4 |
37 |
0.2 |
|
50 |
1.3 |
50 |
1.7 |
46 |
0.3 |
|
75 |
1.5 |
75 |
1.9 |
53 |
0.4 |
|
100 |
1.6 |
100 |
2.0 |
60 |
0.5 |
|
150 |
1.8 |
150 |
2.2 |
66 |
0.6 |
|
200 |
1.9 |
200 |
2.3 |
76 |
0.7 |
|
300 |
2.1 |
300 |
2.5 |
84 |
0.8 |
|
400 |
2.2 |
400 |
2.6 |
94 |
0.9 |
|
800 |
2.5 |
800 |
2.9 |
105 |
1.0 |
| |
|
|
|
115 |
1.1 |
| |
|
|
|
128 |
1.2 |
| |
|
|
|
140 |
1.3 |
Note: Most hot water heaters are set between 120 degrees to 140 degrees.
Since water is much more likely to scale at higher temperatures, it is more important to evaluate the temperature
at the highest potential temperature.
We recommend to always assume that the highest temperature that the water will reach is 140 degrees.
If the Factor Value for this temperature (1.3) is always plugged into the Saturation Index Formula, you will ensure that the index value will be
very reliable.
Once the testing is completed, we then find the corresponding Factor Value associated with the test results for
each component of the formula. According to the test results stated above, the corresponding Factor Values are as follows:
The Hardness Factor is - 2.1
The Alkalinity Factor is - 2.2
The Temperature Factor is - 1.3 (according to the footnote above)
The pH Factor is always the actual pH level of the water (no Factor has to be computed for the pH level).
Now setup the formula with the Factor Values to determine the Saturation Index Value.
Again, the formula is:
Saturation Index Value = pH + Hardness Factor + Alkalinity Factor + Temperature Factor - 12.1
Thus, Saturation Index Value = 7.2 + 2.1 + 2.2 + 1.3 - 12.1
This formula equals an Saturation Index Value of 0.7 which is less than the 1.6 Maximum Index Value Limit.
You can now rest assured that the Aquafer Water Source
or Maxicure will be optimally effective at preventing this water to create scale.
This testing will go a long way to ensuring
you that the Aquafer Water Source
or Maxicure will work for you!
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