Hello, I have been reading many post on this. I am confused at how to do this test. When doing the test and pouring the solution into the test bottle with black dot...do you wait till you no longer see the black dot? Or do you stop when the black dot just starts to fade?
I was doing it when I no longer seen the dot but the pool store told me that you do it when it starts to fade then stop....it was odd because with there test they came out at 100-CYA and when they used my tester it came out 80-CYA
Any help would be appreciated. Thank you