Swimming Pools & Hot Tubs

Germicidal UV Applications  /  Residential & Commercial  /  Swimming Pools & Hot Tubs

Fun or Danger?

Most people associate a swimming pool with carefree, recreational fun. But there is an inherent danger in immersing yourself in a body of water shared with other people, who may carry germs which can easily spread.

While chemicals used in pools and hot tubs have a long history, germicidal ultraviolet technology has has taken pool disinfection to the next level. Installation of a UV water purifier reduces the use of harsh chemicals and tackles microorganisms resistant to chlorine.

Boy swimming underwater / couple in hot tub
Louis Pasteur examining beaker in a laboratory

The Discovery of Microorganisms

In the mid-1600s, scientists began to discover precisely why a body of water becomes tainted over time. Using primitive microscopesopen_in_new, microorganisms were observed infesting water after people used it. In the late 1800s, Frenchman Louis Pasteur pioneered the deeper study of disease-causing microorganisms. But a practical means of killing the viruses, fungi, and bacteria that manifested in bodies of water was not implemented until 1908, when chemical disinfectionopen_in_new of water first began. Chlorine and Bromine have since become the primary means of killing unwanted organisms in drinking water. The are also used in swimming pool and hot tub disinfection.

Jug of chlorine by swimming pool

When swimming in a pool, who isn’t tempted to fully submerge their entire body from head to toe under the waterline? Doing so exposes your orifices to billions of germs that may live in the water. You might think you are a bit safer in a hot tub. But no, the relentless splashing water from the jets likely circulates microscopic pathogens in that warm, moist environment conducive to a thriving bacterial population.

Microorganisms you might encounter in a typical swimming pool or hot tub:

Common Ailments

According to the CDCopen_in_new, recreational swimmers most commonly experience the following, if infected by these pathogens: diarrhea, vomiting, rashes, ear pain, coughs, congestion, and eye pain. These can come about via swallowing water or even breathing in the air and mist that has evaporated from infected water. Of these symptoms, diarrhea is clearly the most prevalent. It has been observed that most people have .14 grams of feces on their bodiesopen_in_new at any given time. A person experiencing diarrhea should avoid entering a pool with other people at all costs, because those germs can easily wash off their bodies and infect others. Children, pregnant women, and those who are immune-compromised are the most susceptible to contracting illnesses from swimming pools and spas.

Boy with stomach ache next to swimming pool

Water Treatments

Chlorine, administered under the proper pH conditions (between 7.2 and 7.8), does an excellent job killing most parasites, bacteria, and algae that infect swimming pools and hot tubs, but using this method comes at a price. The byproducts of chemical treatment are many. While most people are familiar with chlorine, they may not be aware of the compounds called chloramines, which actually create that distinctive smell we commonly associate with chlorine-treated water.

Free chlorine in your swimming pool or hot tub has a tendency to react with nitrogenopen_in_new and bodily wasteopen_in_new (sweat, dirt, and urine) in the water. As a result, mono-, di-, and trichloramines are created. The negative effects of these compounds can’t be overstated. Eye, nose, throat, and bronchial tube irritations are frequently the negative impacts of a routine chlorine regimen. Chloramines can also contribute to metal corrosion in and around the pool in components such as filters and pumps. Good air circulation (for pools and spas located indoors) as well as requiring showers prior to pool entrance are practical ways to inhibit the creation of chloramines. It is also imperative to carefully monitor your pool chemistry and maintain it at the recommended levels. It can be a bit of a balancing act, but good pool chemistry will yield the safest, healthiest, and most germ-free pools.

Process of pool chlorine reacting with nitrogen and producing chloramines
Cryptosporidium oocysts in pool water

Chlorine-Resistant Pathogens

To complicate matters even further, there are microorganisms which are immune to typical chlorine treatment. One of these is Cryptosporidium. “Crypto” is a parasite with a protective outer shell that causes diarrhea. While it can be spread via numerous means, swimming pools and hot tubs are huge culprits. Hepatitis A and Giardia are two other well-known germs which are chlorine tolerantopen_in_new. To address these pesky pathogens, another strategy must be considered.

UV-C: A Safe, Effective Addition

Recent studies have shown chlorine byproductsopen_in_new to be more damaging to people and the environment than was previously known. A technology has emerged in the last 100 years which not only tackles chlorine-tolerant organisms, but greatly reduces the need for chlorine and other harmful chemicals in swimming pools and hot tubs. This safe, effective, and economically-sound alternative for swimming pool and hot tub disinfection is Germicidal UV.

UV Disinfection is the process by which pool water is passed through a stainless steel chamber and exposed to ultraviolet rays emitted through shortwave, low pressure lamps. The wavelength of 254 nanometers makes harmful microorganisms unable to reproduce, and hence inactive. Simultaneously, chloramines are greatly reduced.

UV water purifier with cutout showing lamp glowing
The view inside a unit: UV-C Disinfection sized for swimming pools.

Because illness outbreaksopen_in_new associated with aquatic centers have vastly increased in recent years, the CDC’s Model Aquatic Health Code (MAHC)open_in_new recommends a supplemental water treatment such as ultraviolet disinfection for swimming pools and hot tubs.

The number of reported cryptosporidiosis outbreaks has increased an average of approximately 13% per year from swallowing contaminated water in pools or water playgrounds.

cdc.gov, Cryptosporidiosis Outbreaks — United States, | MMWR

UV disinfection is beneficial on a number of levels. The pool is disinfected, greatly minimizing the chances of sickness for those using it. Dependance on chemical treatment is reduced. Toxic byproducts are minimized. The benefits of UV disinfection are simply: healthier swimmers, lower maintenance costs, and a cleaner environment.

Since germicidal ultraviolet methods began to be implemented for disinfection of waterborne microorganisms in the early 1900sopen_in_new, UV technology has been fine-tuned into the safe, chemical-free treatment we enjoy today. Thanks to this process, our water is not only safer to drink, but safer to swim and relax in.

UV-C rays destroying DNA

Atlantic Ultraviolet Has Solutions

At Atlantic Ultraviolet, we offer made-in-the-USA UV solutions to meet wide-ranging water volume scenarios. We manufacture industrial-sized units which meet the swimming pool disinfection needs of water parks, aquatic centers, and larger communities. We also have products sized for use in backyard swimming pools and hot tubs. Please see our recommended product lines below and contact a UV Application Specialist for help determining the properly-sized system for your needs.

We recommend your swimming pool water be turned over three times daily, cycled through the pool water filter and UV-C water purifier. For example, a flow rate of 40 gallons per minute (using our SANITRON® Model S2400C) will treat a pool of 19,200 gallons.

Usually, customers can greatly reduce their chlorine use. However, chlorine concentration levels should be kept high enough to prevent reduction in water quality or increase in bacteria levels. Be sure to frequently test and carefully observe your pool water, particularly right after installation. This practice will make you aware of the purifier’s operating characteristics and ensure the desired results are achieved.

People in swimming pools and hot tubs
People in swimming pools and hot tubs

Swimming Pool Disinfection


SANITRON®

Our SANITRON® models treat 3–40 GPM (Gallons Per Minute). They are well-featured and can be easily monitored with the use of several accessories. A sight port, patented dual-action wiper, drain plug, and Easy-Off™ end cap are just some of its features. Models S37C, S50C, and S2400C are NSF® Certified. Model S2400C can be combined to handle larger water flow needs.

Sanitron family of UV water purifiers
Megatron model M250 UV purifier

MEGATRON®

The MEGATRON® product line treats 90–450 GPM. Each model contains multiple germicidal ultraviolet lamps and provides swimming pool disinfection for large facilities. Multiple chambers can be combined to handle larger water flows. All 2024 MEGATRON® models feature a remote electrical enclosure with an HMI touchscreen, water temperature monitoring, and UV-C intensity monitoring. This line also features a manual or automatic wiper system for cleaning quartz sleeves around each lamp, a sight port for viewing lamp operation, digital lamp operation indicators, an elapsed time indicator, and removable chamber heads.

Hot Tub Disinfection


MINIPURE®

Our MINIPURE® product line is compact and economical, treating 1–9 GPM. This line is suited for point-of-use applications like hot tubs. An Easy-Off™ end cap with a clear window plug provides a visual of germicidal lamp operation. Compact models require minimal space.

Minipure family of UV water purifiers
Mighty Pure family of UV water purifiers

MIGHTY PURE®

MIGHTY PURE® models treat 3–20 GPM. They offer superior quality and many standard features. They also have several optional accessories available for monitoring your purifier’s operation. These models can be used in many applications beyond hot tubs. An Easy-Off™ end cap allows users to confirm UV lamp operation.

Need help? Contact Our UV Application Specialists

We will help you determine the right products, and the proper installation method in order to provide the precise ultraviolet dosage for your needs.

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