Is CYA affected by water temp?

May 12, 2012
Jackson, TN
Would a change in water temp cause a change in the CYA test readings?

I checked my CYA last week when the weather and water temp was warmer - in the 80-85 degree range and it was reading 70ppm. We had some cooler weather with rain come through so I checked everything again and the CYA yesterday and it is now showing 50ppm with the water temp dropped back to the lower 70's. I suppose it's possible my initial reading could have been off since I was just learning to use this new test kit but I want to be sure the temp doesn't have anything to do with it before I add any CYA to the pool because otherwise everything is perfect.


Mod Squad
LifeTime Supporter
TFP Expert
Apr 18, 2010
East Texas
Generally speaking........that little of a temp difference and especially not being over the winter period would not account for a CYA loss. Most likely testing.


TFP Expert
Mar 3, 2011
Do pool or spa water samples have to be at "room temperature" before testing begins?
With one exception, no. Our lab has run the pH, total alkalinity, calcium hardness, free chlorine, and cyanuric acid tests on known standard solutions at approximately 104°F, 75°F, 60°F, and 40°F. Only at 40°F did the CYA standard solution test higher than its actual value (after accounting for test variability). All other tests were unaffected by temperature differences. ... ntentID=86