CYA in a sock

[AnnaK]

My experience, for what it's worth:

Monday, 6/28, 06:30
ph 7.6
CYA 30 (consistent with previous tests over the past 4 weeks)

CYA goal 50. Per Pool Calculator, add 946 g CYA.

The CYA I use is mfg'd by Seaboard, 100% cyanuric acid, granular. I added 500 g slowly into the skimmer, basket removed, made sure all product was granules, no clumps. The 2-speed pump ran on 'high'. The CYA swirled in the pump pot for 15 - 20 minutes until it had all gone into the filter. At that point I set the pump to low and left it running.

According to the Pool Calculator, 500 g CYA in my pool would decrease pH by .2 and increase CYA by 11 ppm.

Tuesday, 6/29, 08:30:
pH 7.4
CYA 45

I can readily accept the difference in test results from the calculated expectation because a) the water volume can ever be just a close guess and b) variations in the 'endpoint' of the CYA test.

My past experiences with adding CYA product have been similar: it dissolves faster than what I had read and it's measurable within 24 hours.

[Watermom]

All this may be true for your pool. My experience has been that it takes longer for my pool to get up to the reading that I aim for when I add cya. So, although in some pools it may be in there and measureable fairly quickly, for some pools that doesn't always appear to be the case. Therefore, when I answer posts, I will still continue to advise people to wait awhile before testing again (to save reagents) or adding more. Better to be a little patient that overshoot a target of cya since it could mean a partial drain and refill.

Thanks for sharing!