Everyone who sells swimming
pools is deeply aware of the value of the
liquid water, one of the most desirable
commodities this earth provides. Nowhere
else in our universe do we know of
another place where liquid water exists.
It is indeed the rarest matter of all.
But this is not the only reason water is
precious to us.
Water is the most
necessary substance for life. In fact,
living creatures -- like spas and pools
are basically vessels for liquid water.
Because we work in an industry that
relies so heavily on sanitized water, it
is imperative that we strive to
understand how water reacts under various
conditions. This is not always an easy
task, as liquid water refuses to follow
some of the most fundamental laws of
nature. It is the one substance that
turns into something lighter when it
crystallizes-which is why ice floats. And
even when liquid water cools down to near
freezing it violates one of the basic
rules that heat rises and expands things.
As water cools down below 39 degrees
Fahrenheit, it does not shrink, it
expands! It expands so much that the
coldest water moves to the top, above
warmer water! That's why freezing starts
on the top of the water. We should be
happy it does that. Because of this solid
layer of water on top, the rest of the
water is insulated.
Another weird water fact
is that it accepts more heat energy than
its normal share-a great benefit to life.
Indeed no other substance can transport
as much heat energy. That's how liquid
water normalizes the temperature extremes
in out living zones-it absorbs heat when
there is too much, and it releases heat
if there is not enough.
HARD WATER FACTS
The list of the anomalies
in the behavior of liquid water could be
continued on and on. But we have to
consider one more: Although water,
chemically neutral, it is one of the best
solvents known to man. Water has the
capability to entrap other substances. In
other words, it tends to cluster around
every non-water particle, forming
conglomerations or complexes, as they are
called scientifically.
Water's capacity to
entrap substances results in its high
mineral content. The amount of these
dissolved minerals being carried by the
water determines its hardness. One of the
most common minerals in water is calcium
carbonate, a substance that forms
mountain ranges such as the Alps. When
liquid water evaporated the dissolved
minerals become over concentrated and
must crystallize. This also happens when
the temperature of the water increases,
or when the solubility of the carbonates
in the water decreases. The consequence
is a sediment of those minerals on the
walls of the container -- in our case
spas and pools.
These sediments of
minerals that grown on the container
walls are actually limestone, which is
hard and difficult to remove. Very hard
water can produce these hard sediments
with bad consequences. Unfortunately,
this process is a slow one and cannot be
recognized immediately. Nevertheless, the
effects of hard water are quite
noticeable if left to build up over time.
Today the water lines that the Romans had
used for hundreds of years show
accumulations of hard lime scale many
inches thick, as in the beautiful Pont du
Gard in southern France, for instance.
But it only takes a few
years for hard lime scale to take its
toll on water pipes and equipment. Such
sediment layers in heaters hinder the
transfer of heat.
For swimming pools, the
removal of existing hard lime scale is
usually accomplished by an acid wash,
which interrupts the operation of the
system. Furthermore, the acid can attack
pool walls and open up leaks.
Most water supplied by
water districts in the United States is
well cared for, analyzed chemically and
rendered clean enough for drinking. Most
of it contains a good amount of calcium
content. This is important for proper
taste and a healthy mineral balance.
However, it tends to create deposits of
scale over the years if no preventative
measures are taken.
ROOT OF THE
PROBLEM
Preventing scale can also
be accomplished via water softeners,
which work as ion exchangers. They take
the calcium carbonate and replace it with
sodium. The resulting water is not
recommended for drinking because of the
sodium content. And used in larger
amounts, it also adds salt to the
groundwater. Other chemical additives may
rid the water of calcium carbonate, but
only by risking contamination.
If one is serious about
finding a cure for an undesired condition,
it is essential that he or she find out
what the source of the problem is. In the
case of hard lime scale, the reason for
it's formation is easy to understand with
a few basic laws of crystallography.
The change from the
dissolved calcium carbonate to lime scale
is a phase change from liquid to
crystalline. Any phase change needs a
starting point. Most of the time a piece
of a different material may serve as such
a starting point. Such a piece can be
extremely small, like a speck of dust, a
super molecule or tiny solid particle. If
such starting points are not available in
the water, the crystallization can start
only at the materials that make up the
container walls. The crystallization
grows in layers until it becomes lime
scale.
Once we know what causes
lime scale, the means of prevention seem
obvious. We have to provide the necessary
crystallization points for the minerals
in the water so that the minerals do not
wander to the container walls to find
crystallization points.
How can we do that? By
creating a disturbance in the water that
produces crystallization centers for the
minerals.
Actually, most water
contains huge amounts of such centers.
Almost all of these potential centers
however are entrapped by the water-molecule
complexes and cannot act as
crystallization centers. Therefore, we
have to break a few of these complexes so
that their internal captive particles
become free. Once free, they act as
centers for mineral molecules and form
microcrystals. That leaves less calcium
carbonate to form hard scale on the walls.
MAGNETIC
CONNECTION
Fortunately, an entire
arsenal of complex-busting techniques is
available. The disturbance can be
mechanical whirling, sonic disturbance,
electrical frequencies and magnetic
disturbances. They all reduce the
formation of hard lime scale to some
extent. Lately, magnetic devices have
become more and more popular for a number
of reasons.
Permanent magnet
materials have been developed in recent
decades to be 100 times as strong and
much more durable then the old-fashioned
magnets made out of steel. In contrast to
steel magnets, which weaken with age,
modern ceramic magnets do not show any
changes with age. They keep their forces
so precisely stable that nuclear
submarines base their subpolar, under-ice
navigation on instruments depending on
the accuracy of the permanent magnets. So,
once they are magnetized, permanent
magnets never need recharging or an
energy source, which makes their use most
convenient and unfailing.
The effects of magnetic
fields on running water have been
observed long before these better magnets
were developed. Patents on treatment of
water with magnets appeared as early as
the 1950s. Though these magnets were not
very strong, their effects were described
as making the water appear to behave as
if it was soft, as if its mineral content
was lowered. Noticeably less scale was
produced after prolonged use.
EASTERN INFLUENCE
This technology was used
mainly in eastern countries, which were
lacking a competent and reliable chemical
industry. Hundreds of reports have popped
up in Russia, China, Poland and Bulgaria
detailing the successful use of magnets
to treat water.
Lacking any chemical
means of softening the water, these
countries used magnets to treat water for
irrigation and industrial uses, as well
as for personal use, where improvements
of taste and faster drying were reported.
Many attempts to explain the reasons for
the observed effects were made without
much success. Also methods of measuring
the effects remained unsatisfactory.
In western countries the
use of magnetic water treatment methods
developed much more slowly. Water
softening by chemical means was in
general use and the difficulties of
explaining and measuring magnetic effect
on flowing water kept it suspect in
western minds. In addition the chemical
industry tried to discourage its
utilization for obvious reasons.
However, the practical
effects of magnetic water treatment were
undeniable after prolonged use. A number
of companies took advantage of the
situation in western countries to market
magnetic devices for water treatment,
often equating magnets with magic or
mysticism.
But there is no mystique
in how magnets work to treat water
problems. For example, the agriculturally
oriented California State Polytechnic
University in Pomona, Calif., Pioneered
the reuse of irrigation water by using
magnetic water treatment devices. The
positive effects of magnets on water was
confirmed in the 1980s through systematic
research. With the scientifically sound
knowledge of the processes involved, it
was then possible to develop treatment
devices with the newest permanent magnets.
Also a quantitative method evolved for
evaluating the effectiveness of the
devices.
NEW TECHNOLOGIES
The new devices had a
great effect on water treatment. Not only
was the formation of scale totally
eliminated, the removal of scale deposits
in old water pipes could be accomplished
in relatively short times. This had taken
years with the older devices.
How can magnets do that?
How can they provide nucleation centers
in the water? The shortage of nucleation
centers in the water is known to inhibit
the capability of the water molecules to
cluster around each foreign particle,
rendering it unavailable as a nucleation
center. The forces of the magnetic fields
on those water molecule clusters is very
weak. However the clusters vibrate in a
number of ways. When they pass a number
of magnetic poles at a certain velocity
the periodic changes of the magnetic
fields may coincide with one of the
internal vibration frequencies of the
water cluster. Resonance may occur and
result in cracking open such a cluster.
The formerly entrapped particle is set
free, and the nearby mineral molecules
rush from all sides to their nucleation
center, where they form platelets.
The minerals that form
the circular platelets do not have to
crystallize on a container wall. In turn,
the number of hard crystals is reduced
accordingly. This percentage reduction is
the magnetic treatments effectiveness
rating.
Since a method of
quantitatively determining the
effectiveness of the magnetic devices was
developed, manufactures have been able to
maximize their efficiency for industrial
and residential use. Today, there are
basically two types of magnetic water
treatment devices: One is built into the
pools circulation system, while the other
simply attaches to any pipe within the
pools circulation system. In-line devices
are usually more effective than the clamp-on
variety. But naturally, the clamp-on
units are easier to install and are the
most desirable for water systems that
circulate, like a pool, thus giving the
water repeated treatment over time.
Dr. Klaus J.
Kronenberg is a physicist living in
Claremont, Calif., specializing in the
study of permanent magnets. Next month
his column continues with further
discussion of magnetic water treatment's
specific application to the spa and pool
industry.
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