I sure do hope your community pool is maintaining a proper residual amount of chlorine in the water. My guess is they are not. That is why chlorine is so popular - when a child or anyone has an "accident" in the water, chlorine goes to work immediately to sanitize. If there is no chlorine, the tainted water will continue to circulate through the pool until it eventually passes by the ultaviolet light to get sanitized.

I would be surprised if that were so. My company was part of the FDA study for UV sterilization. What we found was that UV radiation was very effective in breaking down and destroying bacteria,although the contact time was excessive. What I mean is the organisms had to be exposed to the light for a long time to be effective. The amount of time varied from about 14 minutes to more than 3 hours (encapsulated bacteria being the longest) What this means is in applications where there is a flow of the medium such as air through a duct or water through a pipe the contact time ( the time any single organism is under the light) is measured in some times a fraction of a second. This has shown and "Immeasurable effect" on colony counts. (It didnÂt kill any of the little buggers) IÂm sure IÂm going to catch flack from some of the people who have a vested interest in uv systems, but there are applications where UV works great. I have two UV sources in every air handler in my home, one above and one below the coils, they are on 24 hours a day and every year or so when I pull open the boxes to check the coils , they are gleaming like they are brand new. Constant Contact time is the key.

I probably should quit while IÂm behind  but that just wouldn't be me :). I wouldnÂt worry about urine in the pool as it is one of the two sterile fluids in your body ( unless you have a UTI or Yeast infection) there is nothing to kill. Its more of a stigma, swimming in it I mean. I like to say " you swim in the ocean donÂt you? Just think what all those fish are doing in there."

joanneswimct,
Health departments usually require commercial pool operators to maintain a measureable amount of sanitizer in the water.
UV, Ozone, and other alternative sanitizing systems are not easily measureable eventhough they are effective.
The cost savings in terms of the amount of Chlorine will probably be small, if any IMO.
For residential pools it's not uncommon to use a layered approach. Ozone/Salt Generator combos are one example. This will become more popular as multi-speed pumps become the norm. Ozone and UV can be used at low gpm where salt generators may not work. Longer hours of sanitizing are more effective.

wbeatty,

I used to have a UV light in my return air duct and a double over my A-coil and it did a great job on keeping any organisms growing on the surfaces. As far as the health in the house, that is difficult to measure, we still had colds and allergies though.

However, I removed them after discovering during cleaning and replacing my air cleaner media and humidifier pad that the frames for these along with the plastic drain pan on my AC coil had been reduced to brittle parts that disintegrated when I touched them.

This was many years ago and I donÂt think the properties of the lights have changed.

FYI: Pool and HVAC use; the bulbs have a distinct life usage and require replacement to be effective on a preset usage hour specification.

z\700,
Things that make you go Hmmmmm ,I cant say what effect UV has on metal, I would think if a lot we would be shielding aluminum from the sun, but I cant really say. :)

Alrighty, then... I guess I'll stick w/ the salt system as this is too much information!! Our town pool will still use chlorine but wanted to try the UV as the air quality under the bubble w/ just the chlorine was horrendous. My swim team has a meet under the bubble tomorrow; the first time we'll be at that particular pool since the switch to UV. It'll be interesting to see if the air quality is any better.
Thanks as usual for all of your replies!
Joanneswimsct

Here are ozone facts form a service perspective. For the record, a UV system is an Ozone system. In the pool industry, it is most referred to as Ozone, not UV.

Can Ozone stand alone? No. Most environmental health departments require a 1.5ppm free chlorine residual at all times if using cyanurites, 1.0 if not. Even Ozone manufacturers will tell you this. Reason being, Ozone cannot oxidize compounds such as ammonia, urea or amino acids. All common wastes. It can do it once oxidized by a halogen such as chlorine or bromine, hence, not a stand alone system. Therefore, urine is a concern as someone said earlier it was not. And, last I saw, urine in a public pool is about as common as a lying politician today. The halogen is also here to protect if the bather load exceeds the output of the unit too.

Ozone is perhaps the strongest oxidizer out there. Sronger than chlorine and kills 25 times faster on E. coli than the killing form of chlorine which is hyprchlorous acid. It does attack from the outside which is why it is so fast.It's also very affective on viruses, spores and cysts. It does promote algae growth though.

On metals, it combines with virtually every metal in the pool environment and forms oxides. They will be filtered if the metals are dissolved in water. Ozone corrodes copper pipes. Somehow, it removes metal from the water but can't remove a stain. It is neutral on other areas that chemicals are destructive such as calcium, sodium and magnesium. A benefit of unused Ozone in the water is that it reverts back to O2.

My opinion, is that the costs do not make it a viable alternative on a public setting as you still need your halogen system and you really are riding on the edge. It's totally dependent on having enough present at the right time and that could be dangerous as testing is difficult.