CYA just won't go down!

whiter0se

Well-known member
Aug 2, 2022
71
NYC
Pool Size
5500
Surface
Vinyl
Chlorine
Liquid Chlorine
The CYA just won't go down or do I just have bad info/luck? I was under the impression that maybe I'd lose 1-3ppm a month. Tested in May (Memorial Day) the CYA was at 70 when I first opened the pool, today the CYA is still at 70.

I shake the test bottles for a whole minute and let it rest for 20 seconds and shake again for a minute so that I am not getting testing errors. I even pour back the solution from the eye-ball beaker into the bottle, shake it up and get a second reading. Always at 70.

Since opening the only thing I've been strictly using 10% LC. Except for 1 bag of 1lb 58% Cal-hypo and that was because I was going away for a week so wanted to bring the FC to near 30 and didn't have any more jugs of LC on hand.
I always try to keep the FC at or above 6-7ppm, the water is clear, it's good, it feels soft and great. I haven't had the need to add any pH increaser or TA just because those levels are within range.

Do I just have bad luck or am I under the wrong impression that the CYA is supposed to dissipate 1-3ppm over a few weeks/months?
 
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The CYA test does not have that kind of resolution. If your water temperature is regularly below 80F and the UV is not as intense (clouds, shade) you likely will lose very little CYA.
My pool, water temperature at or above 90F in the summer, with intense UV all day, loses about 10 ppm more or less a month in summer.
 
If your pool is happy, you should be happy. Your CYA level is not excessively high, and having a higher cya level actually results in less FC loss. The only time higher CYA levels are a problem is when it comes time to slam.
 
Tested in May (Memorial Day) the CYA was at 70 when I first opened the pool, today the CYA is still at 70.
It's been 7 weeks and at a couple ppm lost per month, may not be enough to 'see' (not see ?) 10 ppm.

That said, I'm kinda surprised you didn't see any loss with all the rain we've had.

But as said above, if the pools happy, so are you.
 
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Thank you all. Been thinking of slamming since there are some areas with black dirt but it may just be the rain and wind blowing in dust from nearby road repaving.

Anyhow enjoy this beautiful blueish color. Look at that sparkle!IMG_1068.jpeg
 
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