Over the last decade or so, pool owners have tried to move away from the use of chemicals especially chlorine which has, as many negative effects to using as positive effects on disinfecting swimming pools and spas. One disinfecting process is the use of Ozone in swimming pools in leu of Chlorine. What is an Ozone Swimming Pool?
Ozone Pool Systems are used as a secondary sanitizer reducing the need for harsh chemicals like Chlorine & Bromide, Ozone is effective oxidizer but only treats pool H2O while passing through the chamber in the filter system, then a small amount of Chlorine is added creating a residual in the pool H2O
Ozone is an effective disinfectant for treating municipal and industrial wastewater, enabling the end user to meet EPA pre-treatment standards. Ozone is effective in treating numerous complex, toxic chemicals.
What is an Ozone Swimming Pool
An Ozone system for pools injects Ozone gas into the pool water for disinfection like chlorine. Ozone Pool Systems are used as a secondary sanitizer reducing the need for harsh chemicals like Chlorine & Bromide.
Ozone is effective oxidizer with a lot of advantages over other chemicals but only treats pool H2O while passing through the chamber in the filter system, then a small amount of Chlorine is added creating a residual in the pool H2O.
Ozone systems produce ozone through two generator types; Corona Discharge and Ultraviolet light. Some systems use both for the best and most complete disinfection.
Ozone also has very little effect on chlorine, especially the form of Chlorine that kills contaminants called (Hypochlorous acid). Ozone is kept busy dealing with other contaminants in the pool water and by the time it attacks chlorine, the chlorine is in the (Hypochlorite-ion) form which is the less effective form of chlorine with a higher pH called Chloramine. This is another advantage of Ozone Swimming Pools.
This is a non-issue in a well-balanced pool. There is very little if any residual left in the pool after Ozone is pumped into the pool. Unlike chlorine, Ozone won’t be affected by sunlight.
Ozone treatment is used in conjunction with chlorine or salt pools with an 80-90- reduction of those sanitizers so there are cost savings.
Ozone is a very effective disinfection agent and can effectively kill and inactivate bacteria, parasites, and viruses It’s also a good oxidizer, which means that it can destroy contaminants in the water. The advantage of using ozone compared to other swimming pool treatment sanitizers is the fact less expensive, healthier, and eco-
Is an Ozone Pool Better than a Chlorine Pool
Since the 1970’s Ozone has been around and used as a sanitizer for Spas and swimming pools. The way Ozone works is pretty simple science. The Ozone molecule contains 3 Oxygen atoms but it is unstable. It wants to rid itself of the 1 atom so that it becomes stable and once again an Oxygen molecule.
In nature, Ozone is formed by lightning discharges during a thunderstorm, which gives the air its characteristic fresh and sharp smell afterward similar to that of chlorine. Ozone is an effective disinfectant for treating municipal and industrial wastewater, enabling the end user to meet EPA pre-treatment standards. Ozone is effective in treating numerous complex, toxic chemicals.
Ozone has been extensively used for water purification, in the Bottled Water industry, but ozone chemistry in water is not the same as ozone chemistry in air. Ozone is also used in Air Purifiers. An ozone air purifier, or ozone generator, can only remove certain pollutants in the air, not including dust or dander.
Nature provides a way, a reaction for the Ozone to shed an atom. This natural reaction is called Oxidation.
In pool water, most contaminants that can make you sick are molecular in size, like viruses and micro-bacteria that are destroyed by the Ozone through Oxidation. Once this happens the Ozone molecule loses an atom and the result is a molecule of Oxygen.
How is Ozone Generated For a Chlorine Pool
Ozone can be developed using a UV bulb that emits a certain wavelength that will split the Oxygen molecule creating an Ozone molecule. Or by producing an electrical charge like lightning that would be on a small scale using a process called Corona Discharge (CD). There are more advantages to using CD over the UV process.
- CD produces more Ozone per unit than UV
- CD is Durable and much harder to break
- CD is compact and takes up much less space
- UV is very easy to manufacture
- UV requires less precision
- CD has a hard time working in higher heat and humidity and for this reason, the bulb may need to be replaced every season.
Pool Ozone Water
A blue-colored gas composed of three oxygen atoms, Ozone is both a man-made and naturally occurring gas present in the Earth’s upper and lower atmospheres. An oxidizer, Ozone can chemically destroy contaminants present in water, making it a highly effective gas for pool sanitization.
Pool ozone system diagram:
Unlike typical sanitization products, ozone is applied to the water within the circulation system and returns to the pool of water in a very low concentration.
Ozone can be dangerous in high concentrations, so it must be produced and dissolved in the water quickly. Because Ozone is an unstable gas, it cannot be stored and transported but instead has to be produced on-site using an Ozone generator.
Ozone is a blue-colored gas that’s made up of three oxygen atoms. Ozone is useful in swimming pools because it effectively kills and inactivates bacteria, parasites, and viruses. Ozone is a good oxidizer, meaning it can chemically destroy contaminants in the water.
Ozone sanitizes your pool water thru the pool’s filtering system. Once the circulated water is returned to the pool or spa, Ozone is present at a very low and safe concentration. Because it does not maintain a residual disinfectant, another chemical, like chlorine or bromine, should be added to the pool to ensure the water is completely sanitized and safe for swimming.
Ozone Generators for Pool Care
Also known as Ozonators or Ozone generators sanitize swimming pool water as the water travels through the pool’s filter circulation system. Before returning the sanitized water to the pool, deplete the ozone supply by gassing it off in the atmosphere above the pool water. Ozone is unsafe to humans if present in large concentrations.
Ozonators produce ozone through two generator types; Corona Discharge and Ultraviolet light. To understand how both function, remember that oxygen contains two oxygen atoms (O2) while ozone contains three (O3).
Corona Discharge Ozone Pool Treatment
A Corona discharge ozonator (also known as a corona discharge generator or CD ozone generator) uses high voltage electrical discharges to create ozone. It sounds complex, but the science is actually pretty simple: the electrical discharges create a ring of energy, and as air flows through that ring, some oxygen molecules get split apart and reassemble to form ozone.
UV Pool System
A UV Ozone Generator is also a method for producing ozone to disinfect your swimming pool. To do this ultraviolet light turns air into ozone, and air needs to be passed over UV lamps that emit light at 185 nanometers.
UV Pool Water System
As the air passes over these lamps, the wavelength energy splits the oxygen molecules which they can then reassemble into ozone molecules. Remember, oxygen contains two oxygen atoms and ozone contains three. When the oxygen molecules split apart, they attempt to stabilize, forming ozone in the process. 
Once the ozone is generated (using either type of generator), it needs to be dissolved into the water.
The most common method is venturi injection. For this to take place, the structure of the device creates a pressure vacuum to draw the ozone gas into the pool water as it circulates through the system.
Advanced Oxidation Process (AOP)
Advanced Oxidation Process (“AOP”) is a powerful sanitizer. In fact, the process of using UV and Ozone together creates hydroxyl radicals, and this is the most powerful oxidizer available for a residential pool.
This system uses a UV water sanitizer partnered with an (O3) Ozone Oxidizer for an eco-friendly process to clean chlorine or saltwater pools. The two work together to make swimming pools clear with a dramatic reduction in the need for chlorine and salt generated in standard pools. When ozone decomposes in water, the free radicals hydrogen peroxy (HO2) and hydroxyl (OH) that are formed have great oxidizing capacity and play an active role in the disinfection process.
Advantages of the AOP Pool Process:
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- Viruses and bacteria are all destroyed– AOP can destroy microbes that chlorine will take hours or days to kill on its own.
- You can reduce chemical use-This applies whether using a chlorine feeder or chlorine generator. While you still need 1-3 parts per million (ppm) of free chlorine, it will take FAR less to maintain that residual. So you add less to the pool, you handle fewer tabs, you can run the generator less, etc. It saves you money and chemical exposure.
- Your water can be crystal clear-You may think you have clear pool water but if you haven’t seen AOP water, you haven’t seen clear. With AOP water you can see details 10ft deep in the water. It is crazy clear.
- You will not have any chlorine irritation chloramines-The vast majority of chlorine complaints are actually due to chlorine bound up with other things in the water, creating chloramines. Chloramines smell, they are irritating and burn your eyes. But AOP destroys these, so no chloramine
- Ozone has a neutral pH (about 7.0), so it does not affect the pH of the system pool water.
- It has no calcium or alkalinity and no dissolved solids-Ozone does remove trace amounts of dissolved metals such as iron, manganese, and copper by oxidizing them to their highest oxidation state. These medals will precipitate out of the water and be removed by the pool’s filtration.
JimGalloway Author/Editor
References:
EPA- Ozone Water Treatment
EPA-Ozone Disinfection
