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Benefits of Ozone vs. Chlorine:

One of the main problems with adopting Ozone is that there is a higher initial capital cost to the swimming pool

compared to chlorine. However, over the life of the pool Ozone reduces the on-going operating and maintenance costs.

These costs can be significant. Chlorine is famous for destroying pool infrastructures, rusting out ventilation systems and

destroying pool liners etc. Ozone poses no such problems.

The Ozone pool will be much cleaner, which means dirt, grease, oils, organics and other materials will wind up in the filter

system much faster than with chlorinated systems. That is why, proper maintenance of the filter system is important.

Part of the problem in adopting Ozone is that engineers, architects, pool builders and designers are not familiar with the

technology. Some applications of Ozone, particularly systems installed 10-15 years ago were plagued with technical

problems. Even though Ozone systems have been in regular use in Europe and other areas of the world since the 1950's,

pools here have generally relied on chlorine. Since our engineering, architectural and other technical training have all

been geared to Chlorine, it takes re-education to now apply Ozone. Many people in these industries are reluctant to "shift

gears" and take the time to educate themselves about the proper application of Ozone.

What is the difference in technologies? Chlorine is a complex man-made chemical that found original use in the infamous

"mustard gas" of the First World War. Ozone has been in use for over 100 years, primarily in Europe and was first put to

use for water purification, odor control and in medical hospitals (it is still being used medically today, though not

commonly in North America).

Ozone is made from Oxygen or O2, which is converted through electricity to Ozone or O3. Ozone is a much more powerful

oxidant than chlorine. However, the "shelf life" of Ozone is limited. It must be manufactured and used on-site. This is done

through Ozone Generators which convert Oxygen in the air into Ozone.

As well, Ozone is considered a "short-term" disinfectant and chlorine is considered a "long-term" disinfectant. Chlorine is

also an entrenched technology. It has been widely used in North America and was first adopted at the turn of the century.

It is still the reigning champion of disinfection and has many supporters in the chemical and swimming pool industries.

Looking at the numbersI took out my calculator and started to check what might have gone wrong

at Joes customers pool. Follow my steps:1) 1 cubic meter (m) = 1 million grams (g) of water2) 1 g ozone dissolved in 1 m creates an ozone concentration of 1 part

per million (ppm).3) 100 g of ozone dissolved in 100 m

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pool will create a concentration of1 ppm.4)A residual ozone concentration of 0.03-0.05 ppm is typically

recommended for chemical-free swimming pools. Lets say that 0.04 ppmresidual would have done a good job for Joes customer.

5) 100 g x 0.04 ppm = 4 g of ozone dissolved.6) At a pool water temperature of 25 degrees C (77 F), half of the ozone is

destroyed every 15 minutes (half-life of ozone at that temperature = 0.25 hour

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[h]). Therefore we need to inject 4 times more ozone in order to maintain theconcentration every hour. As a result, at least 16 grams per hour (g/h) of ozoneshould have been dissolved to maintain the required concentration in the pool.