What is UV light?
Published on Feb 26, 2015

UV Light as UV Disinfection

UV is a natural component of the electro-magnetic radiation emitted by the sun. The majority of radiation produced during this process is absorbed by ozone in the Earth’s upper atmosphere. UV light, specifically UV-C light (240-280 nm), which does pass through the atmosphere, acts as a natural disinfectant by inactivating exposed microorganisms, such as those found in surface matter.

Pentair Aquatic Eco-Systems Low-Pressure (Monochromatic) UV Lamps utilize the same principle as the sun. Much of their output energy (35-40%) is within the Germicidal Action Spectrum (240-280 nm), specifically 254 nm.

Coincidentally, living microorganisms absorb UV-C light, which, within seconds, triggers a photochemical reaction in the organism’s DNA thus preventing it from multiplying. The effectiveness of UV disinfection relies on the applied UV dose (i.e., the result of the time and UV intensity that the microorganism is exposed to within the UV System).

Successful ultraviolet disinfection demands strict adherence to Established Engineering Guidelines. We understand the importance of openly sharing critical UV performance information with the public. Our approach is simple. Education instills confidence with the equipment which leads to successful operation. Ultraviolet sterilization is unmatched in its efficiency, simplicity, and dependability when applied as a microorganism disinfectant but does have its limitations. Realizing both the benefits and limitations of UV disinfection establishes a foundation for its successful application.

Ultraviolet Disinfection's Benefits and Limitations

UV Benefits:
UV treatment takes place only inside the UV vessel (exposure chamber) and leaves no residual downstream. Therefore, it is harmless to the animals in the pool. UV Disinfection is a proven solution to harmful waterborne pathogens commonly associated with aquatic recirculating systems. In contrast, chlorine/bromine leaves a residual in the water that can irritate the skin and eye tissue of mammals, reptiles, and birds. Ozone, if not measured and controlled properly, is capable of causing severe tissue damage, even death in fish and invertebrates.

UV Limitations:
Exposure time between the waterborne microorganism and the UV-C light is critical to achieving successful UV Disinfection. The condition of the application’s water (%UVT) will determine how well the UV-C light penetrates through it. UV-C is absorbed by the targeted microorganism or by other organic waterborne particles. It is for this reason that UV equipment should be positioned after the mechanical filter.