I have a quick question regarding the chlorine test. After I add the powder, I add a drop of R-0871. I swirl the water. It turns clear....if I wait 1 minute it starts to turn pink again. This continues to happen for a number of drops. Do I keep adding drops until the liquid stays clear after waiting and then take the measurement? Or is it the initial clear reading that tells me my FC? For instance, right now I am on drop 5 and it is still faintly pink if I wait for 1 minute or so.