Another shock question

[mwsmith2]

CYA inhibits the action of Cl. Pools with high CYA can go higher with the Cl and not have adverse effects on the liner.

Michael

[kjsmom]

Thanks again, Michael --
Every time I think I'm about to figure it all out, I learn something brand new about which I was totally clueless. I had absolutely no idea cya protected the liner from high chlorine levels.

So, since I kept my CYA around 30, and I shocked my pool at 12-15 ppm, could that be why my liner faded?

PAT

[mwsmith2]

The primary job of CYA is not to protect your liner from high Cl levels. It just happens to do so because it inhibits Cl action when it is present in significant quantities, as mentioned before in this thread. Your liner most likely faded due to age, as mentioned by CarlD, a few posts up. If I remember correctly, most liners can take 15 ppm with no problem, but that is the upper limit. Other liner pool owners may remember better than I.

Michael

[kjsmom]

Thanks Michael,
I understand about the cya. There was discussion in the "old" forum that a vinyl liner could take 15 ppm, and I did go that high last Spring in an effort to speed up clearing the water. I know liners do fade over time, but mine was only 2 years old, which I thought was pretty new.

Anyway, I have a new liner, (due to disastrous encounter late last summer with an umbrella during a storm), and I'm going to try to be more conservative with the chlorine. I'm going to try the 60-80 cya and 1-3 ppm cl called for in the Aquarite manual.

I am a little nervous about that because according to the "best guess" chart, 60-80 cya requires a minimum FC level of 5ppm. Maybe the numbers are different with the SWC (I hope).
PAT

[waterbear]

I have an aqulogic SWG and run my cya at around 80 ppm and my FC at 3 pm and have had no problems so far.