13
Rev 13
9.3 Water Balancing
While there are many products to greatly help reduce the amount of “chemical” use and maintenance time,
NOTHING will make your spa totally maintenance and chemical free. If the truth were told everything we
breath, touch and eat is chemical, be they simple elements or compounds or complex organic chemical
compounds that form biological life. One aspect of water chemistry is the
“water balance”.
This is the
water’s tendency to be
scale forming
on one extreme
or being
corrosive
on
the other extreme. In between,
where it is neither, the water is considered
“balanced”
There are four common chemical factors that affect the water’s chemical balance:
o
pH
o
total alkalinity
o
calcium hardness
o
total dissolved solids (TDS)
The first three, along with the temperature of the water, are what determines the overall
“water balance”
.
9.3.1 pH
pH is a measure that tells us how actively acidic or basic (alkaline) the water is. 7 is neutral and below 7
the water is acidic with the strongest possibility being 0. Above 7 the water is basic (alkaline) with the
strongest possible reading being 14. A normal range of pH for hot tubs would be 7.2 to 7.6 or neutral to
very slightly basic. Water that is either too low or too high in pH will be out of balance and will have the
following adverse consequences:
pH –
Normal 7.2-7.6
High pH
Low pH
•
Poor sanitizer efficiency includ-
ing ionizer action
•
Cloudy water
•
Frequent filter cleaning
•
Scale formation
•
Skin and eye irritation
•
Poor sanitizer efficiency
•
Corroded metals/equipment
(early heater tubing failure)
•
Skin and eye irritation
•
Destruction of total alkalinity
Because normally the desired pH is slightly basic, pH adjustment is often done by adding a “total alkalini-
ty” product like
Alka-Rise
which raises the pH but not excessively and forms a reserve or a “buffer”. This
tends to hold the pH at some level, even if acidic products are added, until it is all used up. Beyond this,
there are
pH Booster
and
pH Reducer
products in our starter chemical kit.
All things being equal, bathers tend to make the pH go up in time, although when halogen sanitizers are
used, these make the pH drop. Always make adjustments by adding small quantities at a time. Then allow
the water to completely mix, before testing and adding more. Otherwise you can drive the adjustment too
far in the opposite direction,
