I just bought my first real test kit (K-2006) and tried to test Free and Combined Cl. I used the 25 ml sample size. Free Cl measures 1.0 ppm (5 drops R0871). When I tried to measure CC, I added 5 drops of R0003 and the sample turned a very light shade of pink. I then added two drops of R0871 and it turned clear (I thought) but a minute later it looked pinkish so I added two more drops. I turned clear again, but a minute later was light pink again. This went on until I had added a total of 7 drops and I finally quit.

Am I doing something wrong? Does the sample bottle need to be closed to keep it from turning pink?

Thanks in advance!