How many drops of titrant does it take to have the sample go from pink to clear? If you used a sample size of 10 ml, then you need to multiply the number of drops by 0.5 (or divide the number of drops by 2) to get the Free Chlorine (FC) level. If you used the sample size of 25 ml, then you need to multiply the number of drops by 0.2 (or divide the number of drops by 5) to get the Free Chlorine (FC) level.

If you counted 28 drops and used a 25 ml sample size, then that would be 5.6 ppm FC which is certainly higher than 3, but is probably the accurate number.

Richard