Are CYA Tests Unreliable?

[NullQwerty]

Hey folks,

Last summer and this summer I noticed that my Chlorine level was diminishing quickly. I was thinking it might be my CYA level causing it. So I tested my CYA using my drop test kit (standard $20 kit from Walmart) that I just bought. It showed next to nothing for CYA (i.e. it was too low to give a reading). So I picked up 6lbs of 100% CYA stabilizer and broadcasted out through the deep end of my 24k gallon pool. I left the pump running all night and 24 hours later I tested it again. Too my surprise though I didn't show any change in reading.

So, is it that it can take a long time for the CYA to dissolve and change the water chemistry? Or could it be that my new test kit's CYA test was a dud? Or is it that the CYA tests in general are unreliable? Or anything else?

Thanks!

 

[JasonLion]

The black dot CYA test is not very precise. The actual level can be noticeably different than what the test reads, but should be somewhere in that general range. Other CYA tests are worse, and can be off by much more.

Also, CYA does take a long time to dissolve. We recommend waiting a full week after adding CYA before testing the level, to make sure it has all dissolved.

 

[silver02gt]

From my limited experience on here it can take 3-4 days for the CYA to fully dissolve into the water, and up to a week to fully register on the test. So wait another 5 days or so to retest. According to the pool calculator it should be boosted up to 30 ppm. Best of luck!!!

 

[NullQwerty]

Ahhh....Ok. That makes more sense now. I was definitely scratching my head.

Thanks guys!