The Role of UV Systems for Safe Pool Water

Most pools rely on chemicals like chlorine to keep their water clear and safe. But the same UV technology that can be used to disinfect the water entering your home can be used to keep pools clean as well. While UV systems have become increasingly common in commercial pools as a secondary cleaning process, they are worth considering for private pools as well, especially if you’re looking to decrease your chemical usage.

UV systems expose water to ultraviolet light at a specific wavelength that alters the DNA or RNA of any organisms floating in the water. This includes bacteria, viruses, algae, and protozoans – basically anything alive that can turn your pool water green or cloudy or make it unsafe if accidentally swallowed. Once their DNA or RNA is changed, organisms can no longer reproduce, making them harmless. Algae can’t bloom, and germs can’t make you sick.

In a pool UV system, the water flows through your existing filtration system and then through a graphite housing which contains an ultraviolet bulb. Afterwards the water is pumped back into your pool, free of all living contaminants. Swimmers are never exposed to the ultraviolet light, and no harmful byproducts enter the water. While small amounts of chlorine must still be used to ensure water stays clean between filtration cycles, the amount of chemicals needed to keep the water clear is drastically reduced.

Although installing a UV water filtration system is an investment, there are several reasons it makes sense.

Few people like the smell or side effects of chlorine, but it’s known as a necessary evil to keep pools clean and safe. Although UV systems don’t eliminate the need for chlorine entirely, they reduce the levels so drastically that you may not even be able to tell it’s in the water anymore. That’s also great for your eyes, hair, and skin, which can all be irritated or damaged by the chemical.

In addition to being irritating, chlorine is also expensive, and if you don’t add it fast enough, your water will cloud and you’ll need even more chemicals. Although a UV system requires an initial investment, you’ll typically recoup that money over a few summers by having to buy significantly fewer chlorine tabs and other chemicals like shock and algaecide.

The stinging, eye watering smell most associated with chlorine is often actually caused by chloramines, which are formed when chlorine mixes with sweat or urine. Chloramines are particularly problematic in indoor pools, where they outgas and the vapors are trapped inside, impacting air quality. Ultraviolet light breaks down chloramines, so they will be removed from your pool every time the water passes through the system, making the swimming experience more pleasant.

Although many private pool owners are most concerned with keeping their water clear, it’s also important to keep it free from microorganisms that could make swimmers sick. These often come from other swimmers, especially young kids wearing inadequate swim diapers. Some of these parasites, including Cryptosporidium, Giardia, and Legionella, are resistant to chlorine but disabled by UV light. A UV system provides an extra level of protection for public pools or ones with a lot of young swimmers.

Before adding an ultraviolet filtration system to your pool, it’s important to understand what it doesn’t do.

Ultraviolet filtration systems drastically reduce chemical usage in pools, but don’t replace it entirely. Since water is only treated when it passes through the filter and the UV casing, a low level of chlorine is necessary to control any contamination that occurs from swimmers in between filtrations, as well as to prevent any algae growth in any filter “dead spots.” However, this reduced level is so low that many swimmers don’t even notice it’s there.

A UV system will radically decrease the amount of chemicals you need to dump in your pool, but it doesn’t mean you can ignore pool maintenance. Ultraviolet bulbs and the sleeves surrounding them need to be replaced per the manufacturer’s instructions (typically once a year) or their disinfecting power will fade over time.

Rest assured that the light used to clean your pool is completely self contained in a casing installed near your filter unit. There is no chance that swimmers will come in contact with any UV rays (except from the sun!)

UV filtration is used around the world for safe, cost-effective water purification. Why not put it to work in your pool too? Although it shouldn’t be used as your sole method of pool water treatment, there are many benefits to adding it as a secondary process. This important water purification technology is good for your health, good for your wallet, and makes the swimming experience much more pleasant by drastically reducing your chlorine usage.