Simpool pH model
INSTRUCTION AND MAINTENANCE MANUAL
Programmable digital peristaltic pump
ENGLISH
ADSP7000407
rev. 1.2
27/03/2015
77/313
ANNEX H
–
POOL PARAMETERS BALANCE
The Taylor balance diagram is a practical tool to keep the pool's water well-balanced: you can control an outdoor
residential pool by monitoring the pH, the TH (or Total Hardness) and the CAT (or Complete Alkalimetric Title).
The CAT, or Complete Alkalimetric Title, indicates the rate of
bicarbonates and carbonates diluted in the water in
French degrees, “F” (each degree corresponds to 10 mg/l).
For instance, water with CAT = 12°F corresponds to 120 mg/l of carbonate diluted in it.
Water with high CAT is called “buffered” water, as it reduces the effect of the acidity (pH) correctors. If the CAT is 0,
the pH will never be stable.
When the pH reducer is added, the CAT tends to decrease.
The
TH, or hydrotimetric title, expresses the sum of the calcium and magnesium salts, that is the water hardness,
again indicated in French degrees, “F”.
Changing the water's total hardness is very difficult. This means that it is
almost a fixed parameter in a pool, even if it can be increased by adding calcium and reduced with descaling
treatments and water softeners.
To extend the life of parts used to collect and transport water, the TH should be between 8°F and 18°F and
preferably never above 22°F-25°F.
The water supplied by the mains public network is generally well-balanced.
The water's pH must be measured the first time the pool is filled up and if this pH value is suitable, i.e. between 7
and 8, it must be considered as the “ideal pH” (setpoint) to go back to, if necessary, during the bathing season.
As a first approximation, for soft water set fairly high pH balance values (between 7.6 and 7.8), while for hard
water, strongly mineralized, set low pH balance values (between 7.0 and 7.4).
Taylor's Water Balance
allows to immediately associate these 3 parameters to obtain well-balanced water with a
diagram that connects them.
Just measure the pH, the alkalinity (CAT) and the hardness (TH) of the water. On Taylor's water diagram trace a
straight line between the hardness and the alkalinity. Find the balance point for the pH (where the line meets the
pH axis on the diagram) and, in relation to the balance area identified, examine which kind of products you need to
use:
Area
a
(below the fuchsia. line): not acceptable, the water is too calcareous. Use descaling products to
reduce the TH and the CAT.
Area
b
: area with minimum tolerance for the pH value, between 6.8 and 7.2 (Hard Water with
30°F<TH<40°F)
Area
c
: area where the balance needs to the maintained;
Area
d
(above the Orange line): area with TH and CAT values that are too low: in this area it is necessary
to maintain the hardness and alkalinity at the top limit (the CAT must be maintained at 5°F, the TH at 10
°F).
