Re: Jandy SWCG's "optimal" water conditions: why raise CYA?

Originally Posted by
BigTallDumbGuy
I ordered my Taylor K2006 test kit via Ben's link and I am waiting for it to arrive so I can do proper testing. You may remember that I had an extremely bad experience with CYA a few years ago and I would like to know who sets the 80 PPM standard for SWCG Pools, and why.
The manufactuers and for some of them it's as high as 100 ppm such as for the unit you have. Actually, a lot of it came from discussions on here and on TFP and chem geek is an integral parto of it. It came from the range that SWCG manufactuers recommended and it is the upper limit for most of them (Some units, set the upper limit at 100 and Penair sets it at 85. I don't know of any that set the upper limit at 50 ppm btw.) It was determined that SWCGs operated most efficiently at the upper limit of CYA and had the best pH stability.
My SWCG owner's manual says 50 PPM of CYA, and I believe I read one of ChemGeek's post that says the higher above 50 you get the CYA, the more it actually counter acts with chlorine. In addition, I still need to run my filter at least 4 hours a day for a good turn over.
No, I think you have that confused. There is evidence that above 60 ppm CYA has a direct UV blocking effect in water. Chem geek wrote quite a bit on that either here or at TFP, I can't remember which.
Also, if I remember correctly you have a compupool CPSC-24 which has a MINIMUM CYA level of 40-60 ppm and a MAXIMUM level of 100 ppm (as do many of the Australian units) so your CYA should be at 100 ppm and your FC at 5 ppm. When you posted about burning eyes your CYA was at 50 ppm and your FC at 5.
SO HERE IS MY QUESTION TO ANY AND ALL POOL OWNERS WITH A SWCG THAT KEEP THEIR CYA AT 80 PPM AND THEIR CHLORINE AT 4.0 OR HIGHER, DO YOU EXPERIENCE OR GET COMPLAINTS ABOUT BURNING EYES? BE HONEST, BECAUSE THAT WAS MY EXPERIENCE.
I have never known CYA to cause burning eyes (and my own has been at 80 ppm for several years now). pH problems can cause burning eyes. Chloramines can cause burning eyes (and with high CYA and bad pool management it is very possible to have persistent chloramines.)
YOUR CYA should be at 100 ppm. If you don't believe me look on your manual on the first page after the table of contents where it says at the bottom that CYA should be maintained at 40-100 ppm and that 40-60 ppm is the MINIMUM where it should be maintained. I have explained many times WHY higher CYA is beneficial in a salt pool (and for that matter it is often beneficial in a non salt pool, as Ben and the mods can tell you also.)
When you posted problems of eye irritation it is very possible that your FC was very high since you said it was 5+ and you did not have a test kit capable of testing high chlorine levels (or FC for taht matter so it is possible that you also had chloramines present and that would explain the eye irritation.)
Bottom line, it's your pool and you can do what you want but if you want ot minimize the problems associated with salt pools and save money then raising your CYA to 100 ppm is in your best interest.
I realize that you are very slow to take the advice here since you just now ordered a good test kit even though it's been recommended to you for quite some time. I understand that you have a problem with an overstabilized pool in the past (I suspect you were using trichlor at the time) but to try and correlate that experiece with managing a salt pool is comparing appels and oranges. High levels of CYA are not intrinsicially bad or evil but many seem to think so. In acutallity, CYA is the best thing that every happened to outdoor pools. Stabilized chlorine, on the other hand, can be problematic since it continaully causes CYA to rise to levels high enough to cause problems.
Last edited by waterbear; 07-30-2011 at 03:23 AM.
Retired pool store and commercial pool maintenance guy.
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