Pool Chemistry: Hocus Pocus, Guesswork, or Science?

[styopr]

Wow, talk about a lot to wade through for a new pool owner. There seems to be no consensus--or multiple streams of consensus--on how to maintain a pool. Not having a PHD in chemistry forces me to rely on "authoritative sources" who widely disagree with each other. I purchased a home with a 22k pool. After opening, the pool was clear and seemed clean, with: CYA of 150, TA of 150, PH 7.4, and FC of about 2.5. The pool store BioGuard analysis--which seemed authoritative--stated that TA should be 150, FC 1-4, and CYA needs to be in the 30-200 range. Again, 30-200 for CYA. Multiple online sources state that CYA should be less than 50 for the chlorine range of 1-4 to be effective. For a guy like me, you take that on faith. If, indeed, this CYA score is an established "fact," how can the pool industry promote safe levels of CA up to the 200ppm range??? No chlorine levels should be effective at that level of CYA according to certain internet sources. How is it possible the industry is stating this ideal? Is it just cowboy-land still out there with no regard for the science, or is the science itself not established? Or are people just going "on gut."

BTW, I did drain the pool a couple of times to get CYA in the 50 range. Hopefully, the internet is doing me a solid vs. the pool store and bioguard. But the pool did *seem* ok before. We swam in it a lot and it was crystal clear. Again CYA was 150 and chlorine was around 2.5, which the pool guy thought was really high. He liked to see it at 1ppm, per the CDC recommendation: "CDC recommends pH 7.2–7.8 and a free chlorine concentration of at least 1 ppm." Seems authoritative. They should know - their job.

That and then multiple sources say that chlorine is most effective at 7.4 PH, which is untrue according to other source which state that chlorine is most effective at 6.0 ph and loses effectiveness from there. 7.4 - 7.5 PH could not be an ideal for sanitation, but best described as an ok compromise between the needs of sanitation, people, and pool equipment. Pools have been around for thousands of years; had no idea it was still wild west out there as far as keeping the chemicals corralled.