Chemgeek wroteI've been using my TF100 all season on our indoor pool (not spa) and usually have to add another drop of the R 0871 after adding the R0003, so I include the last drop into my total bromine. I almost always get a little pink from adding the 5 drops of R0003.Note that the test is measuring Total Bromine and there is no need for the R-0003 reagent. Combined Bromine is automatically measured in the first part of the test since monobromamine is in equilibrium with a more reactive monobromammonium ion that reacts with the dye in the test. It is this reactivity that makes the combined bromine still effective as a disinfectant (though monobromamine can smell if it gets high enough in concentration).
Am I doing something wrong to get a result out of the R0003?