I have read the entire sticky thread on using bromine in my hot tub and I want to make sure I have everything right. In a few of chemgeek's posts he says that the TF-100 kit can be used to accurately test the bromine level using a conversion factor or 2.25 from FC to bromine.
So, as I understand it, I test 10ml of the spa water by adding a tiny scoop of DPD powder (R-0870) and add R-0871 drop by drop until the solution turns clear. I then multiply the number of drops by 1.125 (which is .5 times 2.25), and the result is the total bromine level. Is that correct?
Is there any need to add 5 drops of R-0003 reagent before dropping in the R-0871? (I thought that one of his posts suggested doing that, but I could be wrong.)