7
User
’s Manual
value is usually expressed as ºHFxm3.
The higher the resin volume of the
system is, the higher will be the quantity
of hardness that can be retained before
the resin gets exhausted.
2.1 WORKING FLOW RATES
Please see the minimum and maximum
flow rates indicated in the “Technical
Specifications” section. If the working
ranges are outside the recommended
ranges, the proper operation of the
system will be affected (excessive loss
of charge, hardness leakage, etc.)
2.2 HARDNESS LEAKAGE
The ion exchange process may be
affected by different factors, which can
reduce its efficiency and cause a certain
level of hardness leakage.
High sodium concentration on water
to be treated.
This may interfere in the
exchange process.
Excessive flow rates.
Since there is
not enough contact time, some of the
hardness may not be retained by the
resin.
2.3 RESIDUAL HARDNESS
Depending on the final use of treated
water, it may be necessary to obtain fully
softened water or, on the contrary, it
may be desirable to leave some residual
hardness.
This system has been designed to
supply fully softened water, but the
by-pass integrates a residual hardness
mixer, which allows the regulation of
the desired hardness degree in treated
water (see ‘Section 7’).
NOTE: For human consumption water, it
is recommended in most cases, to have a
residual hardness between 5 and 8 ºHF if
pipes are made of copper, and between
8 and 10 ºHF if they are made of iron
(for the latter, it is also recommended
to install a silicopolyphosphates filter
afterwards).
2.4 SODIUM INCREASE
Most of the sodium we consume on a
daily basis comes from food, salt is an
excellent preservative and is used as an
additive in prepared products. Sodium
consumption through the water we
drink is rather low when compared with
that obtained from food.
WARNING: As mentioned above,
water softeners reduce the
Calcium and Magnesium concentration
in water by replacing it for Sodium.
Thus, they increase the sodium level in
water.
The maximum recommended sodium
level in water for human consumption is
of 200 ppm. Depending on the sodium
concentration and the hardness of water
to be treated, it is possible that softened
water contains a higher concentration of
sodium than that recommended.
Should this be the case, or if water
is to be consumed by persons who
must follow a low-sodium diet, it is
recommended to install a household
reverse osmosis system to drink the
water. The table below can be used as
a guideline to know the increase on
sodium concentration in treated water
depending on the entry hardness:
Initial hardness in
water (ºHF)
Sodium added by
softener (mgNa/litre)
10
43
15
65
25
108
30
130
35
152
40
173
45
195
50
217
60
260
