So, I got (by my own mistake) the R-7065 CYA 50ppm standardized solution on a re-order. Ok - gives me a baseline to show what CYA test should look like for 50ppm. Waited until new R-0013 arrived, performed test.
This is all fresh stuff from TF Test Kits. (Rebecca is 'da bomb!)
Problem is - I put the R-7065 in the mix bottle, add R-0013 to the top, shake rattle and roll, 30 seconds later - run test. (Have done this now 3 times - 30 seconds, 1 minute and 5 minute waits - all tests the same result.)
Wow! At 50, black dot is visible. Doesn't disappear until almost 20.
This test has always confounded me as it's so subjective. I've read tons on here about this test, back to the sun, side shadow, upside down under full moon, well, you get the drift.
On pool water test, I'm reading (back to sun) 35ppm.
Or, am I? Anybody have any suggestions? Am I doing something wrong?
Again, everything from TF Test Kits.