Moderator note - moved from here: Testing CYA - Just venting...
Interesting reading, and a bit shocked last post is over 6 years old.
I am having issues with this test. I want to make sure the dot is completely invisible, so I strain my eyes, and every time I believe I see the dot, I add more to the tube.
That said, I do believe the CYA has been too low, as my FC has falling quickly in this TX sun.
As far as I can tell, my CYA is now at about 60 ppm, perhaps upper 50's. Since I have an SWG, I've added another canister of liquid instant conditioner.
Hopefully tomorrow night, it will be above 70 ppm.
My cell has been running in shock mode for a week, but I reduced it to 80% yesterday. I added some liquid chlorine, and today my FC was at 9 ppm, which I know is higher than recommended, but I expect that to slowly come down.
Now to a question I'm sure has been asked before - is there no easier way to test the CYA?