Cyanuric Acid Reading

[Mypool12]

Hello,

I just opened my pool today and the water temperature is a chilly 56 degrees. I took a water sample and heated the water in the microwave for 20 seconds. I then measured my cyanuric acid and it was 40. I was expecting a zero reading. Is it normal to have a reading this high when starting the season? I don't want to add chlorine stabilizer and then overshoot my mark. Did I do the right thing by heating the water?

I believe I finished the 2022 pool season with a cyanuric acid reading between 40 & 50.

Any advice would be appreciated.

Thank you.

 

[V___25]

I would say to let your water come to room temperature on it's own before testing. How long has your pump/filter been running? If you just opened today, the pump should be running for a few hours before taking water samples so that the water is good and mixed up.
Did you drain water at the end of the season when closing? I ended my season with a CYA of 40 and had less than 30 when opening. I drained at least a foot water at closing so that's expected.

 

[Mypool12]

Thank you. The CYA came down a little with room-temperature water. My last reading was at 30. I will test again tomorrow.