CYA...

[Tortooga]

Does unused CYA "expire" or "go bad" ???

I have ~ 7,000 gal Intex AGP so last year I bought bucket of CYA @ Leslie's pool store. I added to pool, levels came up, all was happy in the world of my pool.

This year, I set up pool, add water, bleach to get CL in, turn on SWG, add muriatic acid to get PH right, add CYA. Wait a week to test, fill entire tube and it's clear. Hmmm... add a bit more wait a few days test. Still clear. I tried *gasp* test strip, it show 0-20 (or whatever the low is). Hmmmm... take sample to pool store - they say it's ~ 20 ppm. OK, I'll just add a bit more - do that and test again. Still clear in CYA tube test.

So my only thought is that the granular stuff has gone bad... any other explanation? All other tests have been good. I'm going through a bit more cl than I did last year, but I'm guessing that's due to CYA.

Thoughts?

Thanks!!!

** testing with TF-100

 

[techguy]

No, it collects in your pool. But... over winter it has been known to disappear due what some feel is a bacteria.

Your FC will solve it but you may need new CYA. FYI... trust your TF kit.

 

[Bama Rambler]

How did you store it?
Is the consistency of it about the same as it was?

I don't remember a case of it going bad, but we have had reports of it being bought bad, so it's probably possible.

 

[techguy]

Did I mis-read. Do you day you took the pool down over winter and just set it up and filled it with new water?

new water => no CYA. it only gets into the pool when you add it as CYA or use solid forms of chlorine/shock.

 

[RobbieH]

He added CYA from a bucket he had stored at his house, and it did not bring up the CYA in the pool even well after a week.

 

[Tortooga]

Pool comes down.
Stored CYA in the bucket that has sealing lid in basement (cool, dry, dark) - the bucket that it came in when I purchased it.
Just seems weird. I put in way less last year than this year and it tested to what I would expect.
It looks the same physically - white granules. I put it in pool same way (put in sock and dissolve in bucket of warm water) and then pour that into pool. I didn't backwash after.
I'm at a loss... Not earth shattering, just thought I'd see if anybody had this happen. And now debating to get small amount (use all this year) or try for "big" bucket again to store for next year.

 

[Samantha_in_AL]

I think certain brands of 100% CYA are either weaker than others, or age can make a difference. Last year I bought some and added the exact amount the pool calculator told me too. When I tested a week later I found I had overshot my goal big time! This year I had a different brand and had to add a little bit more 2 times to get up to my goal.

 

[Suziqzer]

I've not heard of it going bad, but I suppose it could happen. I bought a used container of it on ebay when I first got my pool because I found a bucket really cheap. It lasted 2 yrs w/o showing any change in effectiveness. Could have something to do with the brand, etc though.

 

[techguy]

As to the age of CYA, I was gifted a bucket from a buddy. It sat in my garage for at least two years and in his for at least that many (I would guess) and it seemed to work fine this spring. The lable was faded and the dust was crusty.