Saturation index
The saturation index (Si) relates to the calcium and alkalinity in the water and is an indicator of the
pool water “balance”. Your water is properly balanced if the Si is 0 ± 0.2. If the Si is below -0.2,
the water is corrosive and plaster pool walls will be dissolved into the water. If the Si is above +0.2,
scaling and staining will occur. Use the chart below to determine the saturation index.
The pool’s chemistry must be balanced BEFORE activating the OmniPL’s optional chlorinator func-
tion. NOTE: If the pool does not have new water, add metal remover and non-copper based algae-
cide to the pool, per manufacturer’s instructions. This ensures a quick, troublefree transfer to the
OmniPL system.
Salt
(When using optional chlorinator function)
Use the chart on the bottom of the page to determine how much salt in pounds or (Kgs) should be
added to reach the recommended levels. Use the Pool Sizing Formula below (measurements are in
feet/gallons and meters/liters) if pool size is unknown.
Si = pH + Ti + Ci + Ai - TDS
Hardness
Calcium
75
100
125
150
200
250
300
400
600
800
Total Dissolved
Solids
Total
alkalinity
°C
°F
Ti
Ci
Ai
TDS
12
16
19
24
29
34
39
53
60
66
76
84
94
102
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.5
1.6
1.7
1.8
1.9
2.0
2.1
2.2
2.4
2.5
75
100
125
150
200
250
300
400
600
800
1.9
2.0
2.1
2.2
2.3
2.4
2.5
2.6
2.8
2.9
0-1000
1001-2000
2001-3000
3001-4000
4001-5000
12.10
12.29
12.35
12.41
12.44
Use: Measure the pH of the pool water, the temperature, water hardness, total alkalinity,
and total dissolved solids. Use the table above to determine Ti, Ci, Ai, and TDS in the
formula shown above. If the Si is equal to 0.2 or more, stains may appear. If the Si is
equal to -0.2 or less, corrosion or deterioration may occur.
Corrosion
Stain
Ok
-0.2
0.2
USE ONLY HAYWARD GENUINE REPLACEMENT PARTS
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