Free
Chlorine
Every
sanitizer has two key functions, to sanitize (kill bacteria and
all
living organisms) and also oxidize (destroy contaminants and
waste).
The most popular pool and spa sanitizer is chlorine.
Chlorine
is also classified as a disinfectant, meaning that it is
capable
of killing bacteria, algae and other organic material
instantly.
All chlorine does the same thing when it is added to the
water,
regardless of the type of chlorine added. It forms free
available
chlorine. Free
chlorine is the form of chlorine that kills
bacteria,
algae and disease-causing organisms. It is the attack
dog that
guards your pool against microbiotic intruders. (In
general,
you wouldn’t want a dog in the pool, but this is an
exception.)
You must
maintain free chlorine at a sufficient level to disinfect
potential
contaminants on contact. The more chlorine in the
water,
the more it can sanitize and oxidize the water. (Remember
that
sanitizing and oxidizing are the processes that chlorine uses
to keep
the water clear and clean.) However, if the free chlorine
level
gets too high, it can make the water uncomfortable for
swimmers.
The trick is to keep the free chlorine level in the ideal
range. In
a swimming pool, keep free chlorine at a minimum of 1
ppm
(parts per million) and a maximum of 10 ppm, with an ideal
concentration
of 1 to 3 ppm.
In spas
the level needs to be maintained at a slightly higher level
due to
the smaller volume and higher temperature. The minimum
level
should be 2 ppm in a spa, again no higher than 10 ppm, and
ideally 3
to 5 ppm.
For more
detailed advice on the specific chemical treatment for
your pool
or spa, contact Cheap Pool Products.
pH
We use pH
as an index to express how acidic or basic a solution
is. (The
scientific definition of pH is “the negative logarithm of the
hydrogen
ion concentration”.) A pH greater than 7.0 is basic, and
a pH
lower than 7.0 is acidic. In pools and spas, it is important to
maintain
the water in the slightly basic range of 7.2 to 7.8. The
National
Spa and Pool Institute (NSPI), the industry association in
the
United States, has set a standard of 7.2 to 7.6 as the ideal
pH.
If pH Is Low:
• The water can corrode surfaces,
metal equipment or
fixtures.
• Swimmers and bathers can experience
discomfort from
burning
eyes and itchy skin.
• The chlorine may dissipate more
quickly.
• The water may cause pitting and
etching of plaster
surfaces.
If
pH Is High:
• Calcium and metals tend to come out
of solution (the
opposite
of dissolving) at high pH levels, creating the
potential
for staining and scale formation. The calcium
and
metals will actually create deposits and discoloration
on pool
walls and equipment.
• Swimmers and bathers can experience
discomfort from
burning
eyes and itchy skin.
• High pH can contribute to cloudy
water.
For more
detailed advice on the specific chemical treatment for
your pool
or spa, contact Cheap Pool Products.
Total
alkalinity is the measure of the amount of alkaline buffers
(primarily
carbonates and bicarbonates) in your water. These
alkaline
substances buffer the water against sudden changes in
pH. Total
alkalinity is considered the key to water balance. It is
the first parameter you should balance when making
routine
adjustments
to your water.
If you
neglect to check the total alkalinity in your pool or spa, you
may have
trouble balancing the pH. You may also notice that pH
fluctuates
suddenly despite your best efforts to keep it in the ideal
range. If
the alkalinity is too low, anything introduced to the water
will have
an immediate impact on pH. Abrupt shifts in pH can
cause
scaling or corrosion of metal equipment and fixtures as well
as other
problems. When the total alkalinity is high, the pH has a
tendency
to drift upward, causing scale to form.
Maintaining
an ideal level of alkalinity will protect your pool or spa
and its
equipment from the harmful effects of sudden pH
fluctuations.
Think of the alkalinity as training wheels: it keeps the
pH in
balance without allowing it to tip too far to either side. Of
course
the pH can still drift upward or downward, but that change
will
happen gradually as long as the alkalinity falls within the ideal
range.
The ideal range of total alkalinity for pools and spas is
between
80 and 120 ppm (mg/L).
When the
total alkalinity is too low, add sodium bicarbonate. If the
total
alkalinity is too high, you can lower it by using muriatic acid
or sodium
bisulfate.
For more
detailed advice on the specific chemical treatment for
your pool
or spa, contact Cheap Pool Products.