Cya Effecting Fc Reading?

[macgd016]

Can a very high CYA reading effect FC and TC readings?

[chem geek]

Can a very high CYA reading effect FC and TC readings?

It shouldn't. It WILL affect the chlorine effectiveness, but not the chlorine test readings. Why do you ask?

[macgd016]

Can a very high CYA reading effect FC and TC readings?

It shouldn't. It WILL affect the chlorine effectiveness, but not the chlorine test readings. Why do you ask?

As I mentioned in an earlier post my pool guy let the FC go really high about 3 weeks ago. It was probably still 12-20ppm a week ago and it still hasn't come down to 10ppm. This was at the same time I found my CYA was through the roof, a recent measurement using dilution suggests it may be 750ppm. I was just wondering whether the FC reading might be effected by the CYA. However, there will be very little FC usage as the pool is still quite cold, 22C and nice and clean and not in use which is probably why its not dropping very quickly.

PS. Many thanks for all your input to my various posts, quite invaluable to me as I struggle to understand what is and has been going on and what to do about it in the short and long term.

Mac

[chem geek]

With an extraordinarily high CYA, you really need to dilute the water to lower it. The chlorine, even at high FC, will not be effective enough to prevent algae growth without a supplemental algaecide or phosphate remover.