once you run out of reagent A and buy a second test kit, voila, second test tube :lol:

You are absolutely correct.

I actaully only ever do the first part of the test... I always find the second part of the test give me a reading of 6 to minus from the first step. So I don't even bother with the second part anymore, just take my first test and subtract the 6 then multiply by 50

I am not saying for you to do it, just that the second test never changes for me, so I am lazy and don't bother with that anymore.