pH and Water
So, what does pH mean for water? Basically,
the pH value determines whether water is hard
or soft. The pH of pure water is 7. In general,
water with a pH lower than 7 is considered acidic,
and with a pH greater than 7, basic. The normal
range for pH in surface water systems is 6.5
to 8.5 and for groundwater systems 6 to 8.5.
Alkalinity is a measure of the capacity of the
water to resist a change in pH that would tend
to make the water more acidic. The measurement
of alkalinity and pH is needed to determine
the corrosiveness of the water. At WaterMicronWorld
Industries, incorporated in all of our water
generator equipment is a special reverse osmosis
filtration system along with UV light treatment
that yields a narrow pH range of 6.9-7. When
it comes to our machines, that's about as good
as it gets!
In general, water with a low pH (< 6.5) could
be acidic, soft, and corrosive. Therefore, the
water could contain metal ions such as iron,
manganese, copper, lead, and zinc…or, on other
words, elevated levels of toxic metals. This
can cause premature damage to metal piping,
and have associated aesthetic problems such
as a metallic or sour taste, staining of laundry,
and the characteristic "blue-green" staining of sinks and drains. More importantly,
there are health risks associated with these
toxins. The primary way to treat the problem
of low pH water is with the use of a neutralizer.
The neutralizer feeds a solution into the water
to prevent the water from reacting with the
household plumbing or contributing to electrolytic
corrosion. A typical neutralizing chemical is
soda ash. Neutralizing with soda ash, however,
increases the sodium content of the water.
Water with a pH > 8.5 could indicate that
the water is hard. Hard water does not pose
a health risk, but can cause aesthetic problems.
These problems include an alkali taste to the
water (making that morning coffee taste bitter!),
formation of a deposit on dishes, utensils,
and laundry basins, difficulty in getting soaps
and detergents to lather, and formation of insoluble
precipitates on clothing.
According to a Wilkes University study, because
of the association of pH with atmospheric gases
and temperature, it is strongly recommended
that water samples be tested as soon as possible.
The study says that the pH value of the water
is not a measure of the strength of the acidic
or basic solution, and alone cannot provide
a full picture of the characteristics or limitations
with the water supply.