Pool water balance and guidelines

The balance of the pool water is determined on the basis of simultaneous measurement of temperature, pH, calcium hardness and total alkalinity.

Calculation of the water balance gives an idea of whether the pool water is aggressive or whether it will cause limescale deposits.

An index value above +0.5 gives:

  • cloudy water
  • limescale deposits on the walls, pipes etc of the pool

 

An index value below -0.5 gives:

  • aggressive water
  • irritation of the eyes and mucous membranes, as well as attacking the mechanical equipment of the pool.

 

The index value is calculated with this formula:
Index value = pH+TF+CF+AF-12.1

pH
TF
KF
AF
12,1
pH
Temperature Factor
Calcium hardness Factor
Total alkalinity Factor
A constant

See the table below for the factor for each parameter in the formula.

Temperature C TF Calcium hardness
mg/l CaCO3
CF Total alkalinity
mg/l CaCO3
AF
20
22
24
25
26
27
28
30
32
34
41
0,52
0,56
0,06
0,62
0,64
0,66
0,68
0,72
0,76
0,08
0,09
25
50
100
120
140
150
170
200
250
300
400
1,00
1,30
1,60
1,68
1,76
1,80
1,84
1,90
2,00
2,10
2,20
25
50
70
80
90
100
120
150
200
300
400
1,40
1,70
1,86
1,92
1,96
2,00
2,08
2,20
2,30
2,50
2,60

We recommend the Autocheck III photometric test kit for determining the water balance. This is in order to obtain an exact value for each parameter in the formula.

 

Autocheck