CYA keeps disappearing

[drichitt]

I have had my pool for 6 months now doing my own chemical maintenance and relying on my local pool supply company. Pool size approx 8k gal, Jandy TruClear salt/chlorine generator. I basically use (7 test) test strips but make weekly visits to local pool company. I am struggling to keep chlorine at proper levels because the CYA keeps "disappearing". My understanding is that CYA is similar to salt in that it does not evaporate. I do not have a pool leak and have not added any water in last 2 months, at least. Periodic rains have kept water levels pretty stable. I have added approx 15 lbs of CYA, over past 3 months since refilling pool and restarting. All of this CYA has been purchased from local pool supply company. On 3 different occasions my water test revealed I had no CYA in my pool and I was told to add various amts of CYA, as calculated by pool supply co. These various amts of CYA have totalled approx 15lbs. I am starting to question what it that my pool supplier is selling me, but it does raise my CYA if only temporarily.
Any ideas or comments?
Thanks

 

[mknauss]

Welcome to the forum! :handshake:

You are right, CYA does not rapidly disappear. It does slow degrade, primarily in warmer water temperatures.

The issue we see is your testing methods. Neither are reliable, repeatable, or acceptable to TFPC.

This forum advocate’s pool owner water testing using a proper test kit. Order a TF100 test kit. It is properly sized for the residential pool owner.

The only other real option for a test kit is a Taylor K-2006-C. Be careful comparing prices because the K-2006 comes in sizes, designated by a letter. The basic K-2006 has .75oz bottles. You need to get the K-2006-C to get the larger bottles that you want.

I also have the SpeedStir. It makes testing much easier.


I suggest you read Pool School - ABCs of Pool Water Chemistry and consider reviewing the entire Trouble Free Pool School book.

 

[PoolGate]

Also please fill out your signature line with your pool particulars. It really helps in diagnosing issues!

Here -> Trouble Free Pool

 

[ar26pt2]

Cannot be understated how important it is to do your own good testing. Pool stores are awful for this. CYA is also a little tricky to exactly measure under best circumstances, but 15lbs of CYA addition should have increased your CYA a lot (=90 for a 20K gal pool). Getting CYA too high is trouble so test test test before adding more. Good luck!

 

[YippeeSkippy]

Cannot be understated how important it is to do your own good testing. Pool stores are awful for this. CYA is also a little tricky to exactly measure under best circumstances, but 15lbs of CYA addition should have increased your CYA a lot (=90 for a 20K gal pool). Getting CYA too high is trouble so test test test before adding more. Good luck!

Take 3 samples to 3 different pool stores (all from the same pool at the same time!) and see what a difference in reading you get. Don't use the same chain which always asks your name/addy before the test so they can't just look up in the computer your last results..... capisce?

Maddie