Aquacal 75090, Owner'S Manual Installation And Operation

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Saturation Index (SI) - Salt:
The Saturation Index is a formula used to predict the calcium carbonate saturation of water, that is, whether
your water will precipitate, dissolve, or be in equilibrium with calcium carbonate.
Water is properly balanced if the SI is 0 ± 0.3. If SI is greater than 0.3, scaling and staining will occur.
If SI is less than -0.3, then the water is corrosive to metallic fixtures and aggressive to plaster surfaces
and vinyl liners.
A high or low SI can cause premature damage to the cell, equipment or pool finish. As a general rule,
higher concentrations of calcium, total dissolved solids, pH, and alkalinity all promote a greater tendency
for scale. Scaling potential also increases with increasing temperature.
pH + TF + CF + AF - SC = SI
-0.3 -0.2 -0.1 0 0.1 0.2 0.3
Corrosive to
metals, etches
plaster finishes,
and irritates
skin Scaling, staining,
and cloudy water
conditions
Ok
Examples:
pH = 7.4 .....................................:
Water Temperature = 84 F .............:
Calcium Hardness = 400 ppm ........:
Total Alkalinity = 125 ppm ..............:
Salt Level = 3000 ppm ...................:
REFERENCE SECTION
Use the chart below to determine your overall water balance. Test water for pH, water temperature, Calcium
Hardness, Total Alkalinity, Salt Level, and use the equivalent Factors (TF, CF, AF, Constant) from the
chart below to determine your Saturation Index. Adjust chemicals to maintain balanced water.
pH = 7.8 .....................................:
Water Temperature = 84 F..............:
Calcium Hardness = 600 ppm ..........:
Total Alkalinity = 200 ppm ..............:
Salt Level = 3000 ppm ...................:
TF
Calcium
Hardness
CF
Total
Alkalinity
AF Salt Level SC
60 F 15.6C 0.4 150 ppm 1.8 75 ppm 1.9 0 - 1000 ppm 12.1
66 F 18.9C 0.5 200 ppm 1.9 100 ppm 2.0 1001 - 2000 ppm 12.2
76 F 24.4C 0.6 250 ppm 2.0 125 ppm 2.1 2001 - 3000 ppm 12.3
84 F 28.9C 0.7 300 ppm 2.1 150 ppm 2.2 3001 - 4000 ppm 12.4
94 F 34.4C 0.8 400 ppm 2.2 200 ppm 2.3 4001 - 5000 ppm 12.5
103 F 39.4C 0.9 600 ppm 2.4 250 ppm 2.4 5001 - 6000 ppm 12.6
Temperature
pH = 7.4
TF = 0.7
CF = 2.2
AF = 2.1
SC = 12.4
7.4 + 0.7 + 2.2 + 2.1 – 12.4 = 0
(Water is perfectly balanced)
Water Test Results #1
7.8 + 0.7 + 2.4 + 2.3 - 12.4 = 0.8
(Water is scale forming)
Water Test Results #2
pH = 7.8
TF = 0.7
CF = 2.4
AF = 2.3
SC = 12.4
Standard Pool Salt