what light do you read the CYA in...

[rannrich]

I remember that there was a thread debating this (before I got my pool) but I cannot find it. Since I am closing the pool today I wanted to be sure to get a good reading. In direct sunlight it is below 40, in indirect sunlight it is 50. So my question, which do I go with - I am leaning toward the 50 and will chlorinate as needed using that number, unless you all tell me otherwise.

Thank You!

[aylad]

I believe that the instructions call for you to read it in bright sunlight, with your back to the sun. That being said, I don't think it matters so much whether it's dim or bright, but that you perform the test consistently every time....if you do it in bright light the first time, then do it with bright light the next time, etc. The test is very subjective, so as long as you are using consistent lighting from test to test you should be okay. And....if it were my pool and there was a question, I would go with the higher reading. Better to have a little more chlorine than you need in the pool than a little less than you need!

[rannrich]

thank you for the clarification, aylad! I have done exactly as you have recommended.

Happy Holidays to you!

[aylad]

Thank you, and same to you..... :)