A review of saltwater pools, ozonation, and UV light
In a recent blog, “5 Reasons to Convert your Chlorine Pool to a Healthier Alternative,” we recapped various research studies that point to dangerous side effects from chlorinated swimming pools.
So what’s the good news? Research and innovation offer clear alternatives to red, burning eyes and dry, itchy skin. You can maintain your backyard resort without harsh chemicals by choosing from these 3 Ways to Sanitize Your Pool—Without the Typical Chlorine Risks.
1. Salt sanitizers (“saltwater pool”)
In recent years, saltwater sanitizers have become a popular alternative to off-the-shelf chlorine for treating water in swimming pools.
Saltwater systems do use chlorine, but they have a key difference: With traditional chlorine, you manually add tablet or liquid chlorine to pool water on an ongoing basis, whereas with a salt system, a regenerative process converts salt into a form of chlorine gas that is injected into the water to disinfect it.
How salt systems maintain pool water:
A salt sanitizer, which is a kind of electrolytic converter, needs to be part of the pool’s equipment system. This system converts salt to chlorine like this: Standard sodium chloride (like regular table salt) dissolves in the water, and is then passed through the system, where electrolysis transforms it into a sanitizing chlorine gas.
Through this process the pool water is converted to a mild saline solution similar to human tears. This salt sanitizer oxidizes (kills) bacteria, viruses, algae and other radicals. The system works on a cycle, regenerating salt to chlorine, and chlorine to salt—over and over again.
Benefits and considerations:
Saltwater pools offer a more comfortable swimming environment and require less maintenance than a traditionally chlorinated pool. Along with producing a kinder, gentler form of chlorine, this saltwater method eliminates the need to handle, store, and add a harsh form of chlorine to your pool water.
While salt systems certainly put conventional tablet and liquid chlorine to shame, they are not always the best option for long-term results. Depending on several variables, salt systems can compromise the beauty and integrity of your pool.
Bottom line, salt is corrosive. Saltwater can wear down certain kinds of deck materials and stonework. Repeated splashing of saltwater onto nearby plant life can take a toll, as the mineral seeps into the soil and onto leaves, flowers, and stems. Salt may contribute to early deterioration of some metal-based pool equipment and accessories as well.
A saltwater pool does make pool care easier. However, although you may not have to buy liquid or tablet chlorine for a saltwater pool, you will need to purchase and add stock salt to your pool on a regular basis as water and salt evaporates out of it. You will also need to replace the special salt cell in the equipment every two to three years, which can easily run $500 to $600.
2. Ozone pool purification
Ozone purification is the most effective FDA-approved water purification method. Also known as O3, or “triatomic oxygen,” ozone is a powerful oxidant that destroys microorganisms, halts accumulation of deposits in pipes and water systems, and requires virtually no harsh chemicals.
How ozone generators maintain pool water:
Ozone water purification accounts for more than 90% of the world’s purified water. It’s popular for a reason: A naturally occurring substance, ozone immediately reverts back to regular oxygen after use, without leaving anything toxic behind.
This purification process requires an ozone generator using either UV bulb or a corona discharge system. A regular molecule of oxygen contains two atoms of oxygen; ozone is created when a third is added.
Produced ozone is passed into a diffuser, which creates bubbles and saturates them with ozone. These ozone-saturated bubbles are then mixed with pool water in a tank. There, ozone breaks down pathogens, resulting in healthy, swim-ready water.
Benefits and considerations:
Ozone is the most widely used purification system around the world. It is hundreds of times more powerful than chlorine, but extremely gentle on swimmers. Ozone-treated water literally sparkles, and feels silky soft on swimmers’ skin. It helps remove metals like iron and manganese, and keeps calcium from forming scale on your tile line and interior surface. Without the typical chlorine load in your pool, you won’t have to worry about chlorine byproducts that cause burning eyes, bleach-like fumes, and faded swimsuits.
However, ozone has a short lifespan of only 20 to 60 minutes, depending on the temperature. When pool water is cycled through the equipment, it gets treated with ozone, but any contaminant that is introduced into the pool water outside of the equipment needs eradication until that water passes through the ozone generator again. Therefore, a tiny amount of added chlorine is needed to serve as what's called a “residual,” ensuring a safe swimming environment.
Ozone generators that rely on UV bulbs do require replacement bulbs about every 18 – 24 months. These special bulbs require special handling and can be tricky to switch out in the unit. For ozone systems that use the more advanced corona discharge, the cells can last five to seven years and are easy to replace.
3. Ultraviolet pool sanitizing light
Ultraviolet (UV) sanitation is a powerful disinfection method that uses short-wavelength UV light (UV-C) to kill or inactivate microorganisms by disrupting their DNA. UV light destroys cysts, algae, viruses, bacteria, and protozoa, and even kills pathogens that are chlorine-resistant, such as E. Coli, Giardia, Cyclospora, and Cryptosporidium.
How UV light systems maintain pool water:
Instead of chemicals, UV light uses a physical process to disrupt the DNA of dangerous pathogens, rendering them harmless. The sanitation takes place in an enclosed chamber inside the pool equipment, where water passes through and is sanitized by powerful rays of UV light. The treated water then circulates out into the pool, creating a fresh, healthy swimming environment.
Benefits and considerations:
UV light is currently used in medical sanitation and sterile work facilities. It is so safe that it is increasingly being used to sterilize drinking water around the world.
The UV method works equally well in hot and cold climates, requires minimal maintenance, and is proven effective for eliminating a wide variety of pathogens. Like ozone, it has no harmful side effects and leaves no unwanted byproducts in the water. When combined with ozone, UV works synergistically for even better results, destroying 99.9% of all pathogens for optimal water quality.
In summary, there is no need to rely on harsh chemical pool treatments to keep your swimming pool safe and clean. Protect your health, your family, and your future by choosing one of these 3 Ways to Sanitize Your Pool—Without the Typical Chlorine Risks.