CYA level of about 110, should I drain?

flyboy320

Well-known member
Jul 23, 2009
216
Burlington, Ontario, Canada
I've had my pool for about 7 years and have done all the maintenance on it myself. I noticed every spring when I opened, I had to add stabilizer to bring it up to about 30 (using the liquidator and 12% chlorine) and I assumed this was due to the pool water being diluted in the summer with rain, thunderstorms, and me partly draining for the winter months. This year I bought a new bottle of the CYA tester (Taylor kit), and it showed my level at about 110 :crazy: I'm guessing the old test bottle was bad, but at any rate, my pool is sitting at that level and I'm wondering is there any detriment with having the CYA at that level? I guess I'll have to have a chlorine level of about 10, would you notice this higher level when swimming? If I drain, is there a possibility the vinyl liner could be damaged, come away from the pool wall (it's about 7 years old)?
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
11,317
Bedford, TX
FB,

You can drain in stages... Drain about 25% and refill, retest CYA, and decide if you need to drain another 25%.

Only draining 25% at a time, should prevent any liner issues..

Unless you are running a SWCG pool, your CYA should be 60 or less..

Thanks,

Jim R.
 

flyboy320

Well-known member
Jul 23, 2009
216
Burlington, Ontario, Canada
Good plan, I'll retest next week, and if the level is still around 100, I'll do as you suggest and drain in stages.

Does the water temperature or PH affect the CYA test (water is still only around 55f and the PH was a bit low when I opened around 7.1 but has since been brought back to 7.5)
 

Jimrahbe

Mod Squad
TFP Expert
LifeTime Supporter
Jul 7, 2014
11,317
Bedford, TX
FB,

pH no, temperature maybe.

Just read something today which suggests that temperature does not effect the CYA test. But I always let the water warm up to room temp before doing the CYA test outside.

May just be an old myth about temperature, but if it has no effect, then warming it up to room temp will not have a negative effect either..

Thanks,

Jim R.
 

Sfpat

Silver Supporter
Jul 29, 2016
116
tulsa
first question to ask is How did the CYA get so high? Have you been using tablets, shock? CYA just doesn't appear on it's own.
 

tim5055

Mod Squad
TFP Expert
LifeTime Supporter
May 11, 2014
10,121
Franklin, NC
I'm guessing the old test bottle was bad, but at any rate, my pool is sitting at that level and I'm wondering is there any detriment with having the CYA at that level? I guess I'll have to have a chlorine level of about 10, would you notice this higher level when swimming?
Sometimes I'm an outlier on this issue. IF there is no reason to drain other than lowering CYA, meaning no algae or other issues then yes, you can wait.

When I bought my current house the best I can figure is that the CYA was in the 250 range. I kept my FC in line for that level of CYA and took it slow over a couple of years and now I have it at my 50 that I want. I did rig up a hose offf of one of the gutter downspouts so that every time it rains "extra" water goes into the pool.
 

flyboy320

Well-known member
Jul 23, 2009
216
Burlington, Ontario, Canada
No issues other than the high CYA level. I think I'll wait and see how it goes this spring and if I can't keep the algae under control I'll try draining some water. It was fine all last summer even though I don't know how high the CYA level was, so I think I should be fine this summer.
 

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