CYA and FC

[Aqua Lab Rat]

Interesting to see this after years of discussion of CYA vs FC on this forum.

CYA and Chlorine in Plain Language

 

[Donldson]

I found this to be the best part:

With a CYA:FC ratio of 20:1, the concentration of HOCl stays pretty constant at 0.02 ppm

Huh, that chart looked a lot like the SWG FC/CYA minimum. Imagine that

 

[YippeeSkippy]

While this is an improvement (awakening!) in the industry, FC rate suggested is still too low for x amount of CYA though.

Maddie

 

[JoeSelf]

the highest FC I saw was 4 with CYA of 80.

 

[Donldson]

Being an industry publication they were attempting to work within the boundaries that commercial pools have to work within today. Since 4 is the hard limit for commercial pools they didn't suggest going above that. Nor could they, really.

Just the recognition that "hey, these FC levels at these CYA levels are all essentially the same" is a first step towards (hopefully) changing the guidelines from a hard FC number to making it a function of CYA. Perhaps one day we can actually hope to see "FC 1-3" changed to "FC 5%-10% CYA". A long shot, but perhaps.

 

[Lemonred34]

I recently looked up the recreational pool laws for my state out of curiosity. They do mention the new studies showing the relationship between cya and FC. If I remember correctly the CYA is not allowed to go over 90 and FC not allowed to be over 10. I was pretty surprised not to see the max “4ppm” I’ve seen everywhere else.

 

[frogabog]

do tests.

tell results.

We got ya.