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Ozone Generators

Ozone for water sanitation is not only healthy but also environment friendly.

These units use the equivalent amount of electricity of a standard household light bulb and are extremely cost effective, not to mention the possible savings on chemicals and chlorine.

Success on swimming pools with ozone can be quite technical and requires an end to end combination of the correct selection of product that is properly installed. An incorrectly installed system will not work and we do not advise DIY installations. All DIY installations are done at own risk and any damage to equipment is not covered under warranty.

Basic unit sizing

For ozone to be effective on a swimming pool, the minimum sizing recommendation is 1g/h per 10 000 litres of swimming pool water, this also caters for variation in the amount of ozone generated by these units due to variances in altitude and climate. The maximum ozone output of units drawing ambient air will vary according to humidity, altitude and airflow. Another important factor is pump run time and a minimum pump run of 12 hours is recommended, but more hours are better. When your pump stops and the ozone generator switches off, there will be no sanitation on the pool. A decent pump run time is crucial to keeping your pool water sanitised and at the same time good for filtration to keep your water clear.  (Litre Calculation: Meters (L) x Meters (W) x Meters (D) = cubic meters x 1000 = Total Litres)

Note: Unit required will vary pending temperature, bather load, filtration system, pump run time etc. For more complex installations, we can provide contactor tanks with off gas systems as well as monitoring and control equipment with air preparation.

Factors reducing Ozone concentration

The ozone concentration in the water declines due to consumption by such "ozone demand" factors as microbes, minerals, and organics. It also has a time exponential decline due to its natural "half-life" (time for the concentration to fall in half). Half-life depends on ozone demand, temperature, pH and other factors. Assuming a neutral pH of about 7 and room temperature, typical ozone half-lives in water are:

  1. Clean, high quality water (10 minutes) 

  2. Water with some chlorine or minor contaminants (1-10 minutes)

  3. Moderately dirty water, water with strong chlorine or organics, etc. (10-60 seconds)

  4. Waste water with significant reaction elements (A few seconds)  

Based on the information above, it is clear that not all similar sized swimming pools will require the same size ozone generator. It is key that bather loads, other water contaminants and the environment need to all be carefully considered when sizing an ozone generator to a specific pool.   

Ozone in swimming pools

Ozone is a highly oxidative product that is more powerful and quicker acting than any of its chemical comparatives such as chlorine or hydrogen peroxide and also known to kill bacteria types that the others cannot through normal safe levels of concentration. Ozone is especially effective in removing odours, precipitating iron and manganese, oxidizing organics as well as killing bacteria and sterilizing the water. It is safe to use and cost effective to operate. Ozone has been adopted by multiple municipal water sanitation plants worldwide and is becoming more and more the sanitizer of choice for swimming pools especially since the ban placed on the use of chlorine in multiple countries. Unlike other sanitizers, especially chlorine that leaves a residue of trihalomethanes implicated as carcinogens in the development of kidney, bladder and colon cancer, Ozone reacts with organic materials to break them down into simpler compounds that are not dangerous. Ozone is also good at breaking down harmful residues created by other sanitizers. There is lots of evidence available to prove that the use of ozone on swimming pools is far superior to the use of any other sanitizer, not to mention the added health benefits.

How it works

Ozone is an unstable compound generated by the exposure of oxygen molecules to a high energy electrical discharge. The weak bond holding ozone’s third oxygen atom is what causes the molecule to be unstable and thus, very effective. Oxidation reaction occurs upon any collision between an ozone molecule and a molecule of an oxidizable substance (i.e. bacteria, fungi (mould & yeast), viruses, forms of iron & manganese…) The weak bond splits off leaving oxygen as a by-product. During an oxidation reaction, organic molecules are changed and dissolved metals are made no longer soluble.

The Technology

The units are based on the following corona discharge principle as indicated in the diagram below. Ozone is generated by creating an electric field between two electrodes that is strong enough to rip apart molecules known as a corona or corona discharge.

Ozogen create a corona discharge inside a reactor constructed of high grade stainless steel combined with high purity ceramic components. This design is definitely one of the most robust and reliable commercially available. We then take this reactor and combine it with solid state electronics concealed in epoxy to prevent moisture contamination and fit this inside a specially designed housing with a cooling fan, protection fuse and neon light to show that high voltage is being applied to the reactor. Heat is an ozone killer so on our bigger units that generate more heat, we add water cooling on larger units to keep the core of the reactor cool and ensure high performance even in the hottest conditions. The corona discharge technology is chosen because it allows large amounts of ozone to be generated in a device that can last for many years unlike some of the other technologies. Ozone Transfer into the swimming pool water - (If this is not right, it will not work)

Air is sucked through the ozone generator using a venturi that is installed on the swimming pool return pipe from the pool filter to the pool. The basic venturi for installations where the pump and filter is located above water level can be easily fitted to 50mm PVC pool pipes by cutting out a small section of pipe and securing the venturi in place with PVC glue. For 40mm plastic pipes or other, simple reducers are used that are available at most swimming pool shops. Installation is generally simple and quick if the pool pump is equal to or above water level. The venturi used by Ozogen ensures adequate airflow through the pool units, to maximise ozone output as well as ensuring a good transfer of ozone into the water. Generally speaking when running off ambient air, you need close on 5x the airflow to achieve the same O3 output as opposed to running off high grade oxygen. It is very important that a venturi is sucking properly and hence they must be properly selected and installed.  If your pump and filter is below water level then the installation is more technical and will require a specially sized venturi be installed to overcome the head pressure and yet still provide suitable suction.  To improve the transfer of O3 to water a static mixer can be used. Below you can download a document that shows you how to make a simple but very effective static mixer for your swimming pool.

Cloudy Water in a Ozone Swimming Pool

Don’t Worry... In This Case, It’s Temporary and Good!!!

Cloudy water can be caused when an ozone generator is first installed because the ozone oxidizes the organics in the water causing them to form a chain which then becomes visible to the eye and gives the water the cloudy appearance. Another way water can appear cloudy is with an imbalance in the water. Always check to make sure the pH, alkalinity and calcium hardness are balanced. Customers are concerned when, within a day or two of installing their ozone generator, their pool water becomes cloudy. The common reaction is to "shock" the water which clears the water for one or two days before it turns cloudy, and they need to "shock" it again. Shocking the body of water with large amounts of chlorine will break down the molecular chains formed by ozone, but is not recommended. Water will appear clear temporarily, but a few days later the shock is exhausted and the ozone cycle begins again, resulting in cloudy conditions. To avoid this cycle, the chains formed by the ozone must be allowed to grow large enough to be filtered.

Basic Swimming Pool Maintenance

For any sanitizer to be effective including ozone, basic pool maintenance must be followed. Below is a basic guide that can be downloaded to advise on pool maintenance and assist you in maintaining your swimming pool clean and sparkling.


Removal of algae on an O3 pool is typically done by throwing 1 x Chlorine tab (Poolbrite "Hi-Tech" tabs are recommended) per 10kl into the weir and running the pump for 48hours. The O3 super activates the Chlorine to rid the algae and then burns up the Chlorine. Next you need to throw in some ALUM (small quantities, 1 tablespoon per 10kl into weir, too much will make your pool milky and reduce pH) to clean up the algae residuals and phosphates. Give the pool a good brush and then vacuum on the following day to waste or backwash immediately after vacuuming. Avoid algaecides on an O3 pool as you loose effectiveness of the O3 whilst it is working against the algaecide, not to mention possible foaming, algaecide smell and other chemical reactions.

For general prevention of algae, 1 x 2L bottle of Poolbrite "Tru Blu" can be added to the pool every odd month.

Ozone is a natural gas that we breathe daily. It is created when oxygen (O2) molecules are split into two separate atoms by ultra violet radiation from the sun, lightning or electric arc. The freed atoms recombine in 3-atom groups to form ozone (O3). The word ozone comes from the Greek word ozein meaning smell, because of its distinctive sun-ray lamp smell. Ozone is nature’s way of cleaning pollution from our atmosphere. How Does O3 Ozone Work?

Ozone tends to react with other substances by attaching the third oxygen atom to the other substance, thereby oxidizing it. Many of us have heard weather reports where the ozone levels were referred to in conjunction with pollution levels. Ozone is present in smog because certain processes that create pollution also produce ozone. Ozone recombines with those same pollutants and neutralizes them by breaking them down into water, carbon dioxide, sulphur, nitrogen and oxygen. Generated low levels of ozone used for water purification prove very successful, as it is possibly the most powerful antibiotic, sanitizer and deodorant known to man. It doesn’t merely mask harmful substances or smells – it seeks them out and eliminates them.

What is O3 Ozone Used For?

Ozone or ozonated water is used to:

Disinfection in hospitals, food factories, care homes etc. / Disinfect water before it is bottled for beverages. / Deodorize air to remove smells etc, such as after a fire. / Kill bacteria on food or on contact surfaces. / Scrub yeast and mould spores from the air in food processing plants. / Wash fresh fruits, vegetables and fish to kill yeast, mould, bacteria and increasing shelf life. / Chemically attack contaminants in water. (iron, arsenic, hydrogen sulfide, nitrites and complex organics) / Eradicate water borne parasites in surface water treatment plants. / Treatment of swimming pool water, Koi ponds, fish tanks water displays. / Ozone therapy, huge success has been achieved and ozone therapy is a well established alternative and complementary therapy used in many countries around the world to treat all kinds of diseases and ailments like cancer, HIV etc.

Comparing Ozone vs Chlorine

1) Ozone is over 3000 times faster to purify water. 

2) Unlike chlorine, ozone leaves no harmful chlorinated by-products in the water, ozone quickly reverts back to pure oxygen if unused.

3) Chemical water treatment leaves long-term chemical effects on the environment, some of which are negative. Ozone does not.

4) Ozone is the strongest, fastest, commercially available disinfectant and oxidant for water treatment.

5) Ozone oxidation reactions take place several thousand times faster than those of chlorine for destruction of bacteria, viruses, yeast, molds, cysts, mildew, and most other organic and inorganic contaminants.

6) Ozone in appropriate doses can treat all water borne pathogens, while chlorine cannot (given practical, safe doses.)

7) Ozone is generated on site and does not require storage.

8) You cannot over-dose with ozone as unused ozone escapes out of the water and reverts to oxygen.

9) Ozone disinfection qualities are not dependent on pH, nor does the addition of ozone affect the pH of water.

10) Ozone oxidizes and destroys oils and other contaminants in water.

11) Ozone can significantly reduce levels of harsh chemicals such as chlorine and their by-products.

12) Ozone acts as a micro-flocculent, aiding in the removal of minerals such as iron and manganese.

13) Ozone leaves no unpleasant chemical taste or smell.

14) Ozone dissolved in water will not irritate skin, nose, or ears, nor will it dry out or leave a chemical film on skin.

15) Ozone's effectiveness can be measured with a simple ORP meter.

16) Ozone is less corrosive than chlorine in water.

17) In view of results of several studies examining the safety of chlorination, many municipalities want to remove chlorine from their water treatment plants all together. The cause for this concern is the presence of chloroforms and other halomethanes in post-chlorine treated natural water. The most commonly encountered contaminants of this type are bromomethanes CHClBr, CHClBr and CHBr along with the afore mentioned chloroform all of which are suspected carcinogens.

18) With the advances in the technology used to generate Ozone, Ozone is becoming more affordable to install and cheap to operate. Typically an Ozone installation will pay for itself over 12 months in chlorine savings.

19) Some say a salt chlorinator is efficient, but remember that over a period of time the salt in the water will damage the concrete and tiling around your pool and also create a toxic bath full of carcinogens.

20) Your body absorbs pool water while swimming; do you really want your body absorbing huge amounts of chlorine and its by-products? Most competitive swimmers will refuse to swim or train in a chlorine pool and chlorine has already been banned in many countries because of its negative effects. 


According to the U.S. Council of Environmental Quality, "Cancer risk among people drinking chlorinated water is 93% higher than among those whose water does not contain chlorine."

Dr. Joseph Price wrote a highly controversial book in the late sixties titled "Coronaries/ Cholesterol/ Chlorine" and concluded that " nothing can negate the incontrovertible fact, the basic cause of atherosclerosis and resulting entities such as heart attacks and stroke, is chlorine."

Dr. Price later headed up a study using chickens as test subjects, where two groups of several hundred birds were observed throughout their span to maturity. One group was given water with chlorine and the other without. The group raised with chlorine, when autopsied, showed some level of heart or circulatory disease in every specimen, the group without had no incidence of disease. The group with chlorine under winter conditions, showed outward signs of poor circulation, shivering, drooped feathers and a reduced level of activity. The group without chlorine grew faster, larger and displayed vigorous health. This study was well received in the poultry industry and is still used as a reference today. As a result, most large poultry producers use de-chlorinated water.

"It would be a common sense conclusion that if regular chlorinated tap water is not good enough for the chickens, then it probably is not good enough for us humans!" 

There is a lot of well founded concern about chlorine. When chlorine is added to our water, it combines with other natural compounds to form Trihalomethanes (chlorination by-products), or THMs. These chlorine by-products trigger the production of free radicals in the body, causing cell damage, and are highly carcinogenic. "Although concentrations of these carcinogens (THMs) are low, it is precisely these low levels that cancer scientists believe are responsible for the majority of human cancers. Breast cancer, which now effects one in every eight women in North America, has recently been linked to the accumulation of chlorine compounds in the breast tissue. A study carried out in Hartford Connecticut, the first of its kind in North America, found that, "women with breast cancer have 50% to 60% higher levels of organochlorines (chlorination by-products) in their breast tissue than women without breast cancer."

***Please note that Chlorine does still have its uses. When a little Chlorine is used on an O3 pool to clear up algae it works exceptionally well as the O3 super activates the Chlorine and cleans up the residuals. This is a lot healthier way to rid algae as opposed to some algaecides***