CYA test question


Well-known member
May 11, 2018
Dayton TN
I have been slacking on keeping an eye on my CYA because I am running low on the chemicals to test. Have had some rain and added a bit of water due to backwashing a few times so decided to run a test this morning.

My CYA level a couple weeks ago was 50, now it appears to be lower than 20 which seems like quite a significant drop to me.

I *did* just add some acid to my pool to bring down my PH, could this be skewing the CYA results?


Mod Squad
TFP Expert
LifeTime Supporter
Apr 17, 2010
East Texas
No. Adding acid to lower your ph will not affect CYA test results. You can pour that CYA test back and forth a few times between the mixing vial and the test reading vial to maybe average your testing results.


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

My experience with CYA is that if you want it to come down, it will not.. If you want it to stay up, it will come down... :mrgreen:

When we get heavy rains for several day, my CYA will almost always drop from 70 to 50 or less..


Jim R.