FC levels with Ultra UV and Clear O3

[flywright]

Does anyone have any data that supports being able to leave the pool at a lower than suggested minimum FC level with the use of the Paramount Ultra UV and Clear O3 combination?
My FC has dropped to less than 1 a couple times for a couple days at a time this summer, and I shocked it, but I am curious if my Paramount equipment has helped, or really any opinions at all about this equipment.

Here are my numbers today.

PH 7.6
FC 3
CH 500 - yikes
CYA 40
TA 60

Thanks.

Rich

 

[BuckeyeChris]

Not for a pool.
UV - Lower FC

If your pool is outdoors and you are not running a public-pool level of bathers, they are unnecessary. I have a ClearO3 also and I shut the valve on it.

For your spa it can do some good to run the ozone right after people get out, then you could use less Chlorine eradicating the waste.

 

[duraleigh]

+1 what BC said. Not helpful for a residential pool.

 

[JoyfulNoise]

UV and ozone both interact with free chlorine (hypochlorous acid and hypochlorite) and oxidize it to chloride. Therefore, depending on the output levels set for the ozonator and the UV lamp source, they both have the potential to drive up chlorine demand. It is also true that ozone does oxidize some bather waste and organics and UV does kill certain specific pathogens better than chlorine (cryptosporidium is one of them). See this EPA Document for Ozone and this EPA document on UV. However, in low bather-load residential pool chlorine oxidizes bather waste just fine and UV only kills pathogens that make their way into the UV cell through normal water flow; any pathogens stuck to the walls (algae) or biofilms in the pipes (bacteria) are unaffected by the UV. As well, many of the pathogens that are claimed to be better killed by UV are diseases that require a sick person to go swimming in the pool; that's a bigger problem for public/commercial pools than for private, residential pools.

So, as previously mentioned, in a residential outdoor pool that gets daily sunlight, chlorine is the most efficient and effective treatment.

Many pages of posts and threads have discussed the issues around using alternate sanitizers and you can easily find them in the search bar. The claim that these systems can allow you to use "less" chlorine is specious at best. If anyone wanted to use less chlorine, then you could do it much more easily by supplementing the water with polyquat-60 algaecide, adding borates to the water and making the water as nutrient-deficient as possible by using a phosphate-reducer product like PhosFree. Then one could possibly operate at a lower FC/CYA ratio. However, one will notice right away that doing so will likely raise the cost of keeping the pool clean because not only is chlorine still being used, but one is also adding more chemicals to the water that are not cheap.

 

[flywright]

Thanks yall.

 

[chem geek]

As for your question of whether either UV or ozone helped prevent algae growth when the FC got too low, the answer is maybe. There is no question that any algae that is free-floating and got circulated would have been killed by the ozone system and at least some killed by the UV system (if the UV is sized for disinfection, then it kills bacteria readily, but algae is a slower kill so not all may be killed). The problem is that not all algae nor pathogens conveniently circulate through the water and many prefer to stay stuck on pool surfaces. In that case, ANY system that depends on circulation through the system will do absolutely NOTHING to kill such algae or pathogens on pool surfaces or otherwise not getting circulated.

Don't forget that the rate of algae growth is also dependent on the amount of algae nutrients (phosphate and nitrates) in the water though such growth is ultimately limited by sunlight and temperature. So it is also possible that your pool was poor in algae nutrients and that the limited algae growth when the FC was low was not due to the UV or ozone systems. In fact, I had a very long discussion in this long thread on another forum where the pool owner wanted to operate with a lower FC/CYA level because his wife didn't want much trace of chlorine in the pool (i.e. not to be noticeable at all by her) and had an ozonator that he thought was the reason he didn't get algae. I found out that he had also used a phosphate remover and told him that it was more likely to be the low phosphates that prevented algae growth allowing for the lower chlorine level. He did an experiment where he turned the ozonator off and found it didn't make much difference but then I had him add fertilizer to the pool to increase phosphates and then he could see that even with the ozonator turned on he could not prevent algae growth in the pool without raising the chlorine level.

 

[BuckeyeChris]

usually it's the pool store that has you dump a bunch of s__ in your pool.