Mar 27, 2003

The O-Zone: Today's Lesson: Design Parameters for Using Ozone on Swimming Pools

Tech Workshop

The main purpose of an ozone pool system is to eliminate the

* 50-100
percent chlorine use

* Detrimental
affects of chlorine

* Chlorine
taste and odor

* Unsafe
levels of harmful microbes

* Cloudiness

* Instability
of the water

* Unusual
feel of the water

The principle of proper operation behind an ozone pool
system is to circulate enough water or gallons per minute (gpm) to properly
interface and mix the ozone and water. The only time the water is ozonated is
when the pool pump is operating. If insufficient water is circulated, then more
chemicals such as chlorine will have to be used.

Ozone is used primarily to make the water safe from harmful
bacteria and viruses. Ozone is not a good algaecide. This is because algae are
plants with roots that can penetrate and/or adhere to the pools surface. Plants
are far more resistant to ozone than bacteria. It would take a far greater
amount of ozone to kill algae than it would to kill bacteria. Most pool designs
in the United States do not circulate enough water to afford the proper contact
of ozone for the elimination or prevention of algae. Europeans pools are built
to a much different standard with greater circulation rates. This is why ozone
is often used in Europe and chemicals such as chlorine are used minimally.

A benefit of an ozone system is the altering of chlorine's
detrimental effects. The taste, odor and other detrimental effects will, in
most cases, be minimal due to the alteration of the chlorine on a molecular
level. Ozone will convert chlorine and chloramines to a dissolved salt,
therefore reducing or eliminating the detrimental effects.

Ozone systems can make a good pool pristine and a bad pool
fair to good. What differentiates a good from a bad pool? Design, care and
organic load.


Once the pool is built there is little you can do. You can
install a larger pump and filter but only to the extent of the plumbing size
and layout.


This is where you can make a lot of difference. Most pool
owners do not take proper care of their pool and are looking for the
"silver bullet" that will yield perfect water quality without doing a
thing. No such luck! Pools are maintenance intensive. Some devices such as an
ozone system will make your job easier, but you still have to perform the
normal/proper janitorial activities.

* Sweep
one to two times per week.

* Vacuum
one to four times per month.

* Maintain
the proper pH, alkalinity, hardness, TDS and algaecide.

* Operate
properly. Most people under-operate their pool. Yes, you will have lower
electrical consumption, but you will make up the difference in chemical use.

Organic Load

This is the amount of leaves, dirt, dust, debris, rain,
run-off and swimmers that enter the pool. Swimmers contribute the highest
organic load with skin, hair, mucus, urine and various microbes.

The following design considerations would be helpful in
setting a pool up for an ozone system.

* Be
sure the circulation rate is at least five turnovers per day. One turnover
means that all the water will go from the pool, through the filter and back
into the pool. Most pools are designed at a far lower rate than this, which
compromises the water quality and the ability to keep it clean and safe. More
chemicals are required to supplement the lack of circulation. This means that
the pump, filter and plumbing have to be sufficient to handle the
increased/proper flow.

* Filter
selection is vital.

- Sand
filters are the least effective at removing particles, and they waste a
tremendous amount of water during backwash and rinse.

- DE
filters remove the smallest particles and, therefore, yield the highest water
quality. However, DE requires slightly more maintenance. The trade-off can be
quite beneficial.

- Cartridge
filters are the most common. Their removal is fair/good and the maintenance is

* The
size of the pool will determine the number of skimmers and returns. Again, most
builders design only what is necessary based on United States standards. This
assumes low circulation rates and high chemical usage. European circulation
rates far exceed the United States. Ozone is the European standard and certain
chemicals such as chlorine are illegal in some areas.

Next month's column will discuss various types of air dryers
and their importance to ozone systems.

About the author

Roger Nathanson is president of Ozone Pure Water, Inc., Sarasota, Fla. His background includes mechanical engineering, plumbing/pipe fitting, swimming pool remodeling/repair, sales and marketing. Ozone Pure Water has been a full service ozone/water treatment supplier since 1980. Nathanson can be contacted at
800-633-8469 or 941-923-8528; [email protected];