I asked my dealer about testing for free bromine and he mentions my tds is at 600. This is my total dissolved solvents which is probably not my free bromine. My total bromine is at 2.9 but ph is still high at 8.4 and total alkilinity is 99. He told me to add 9 tea spoons instead of 3 as my ph is always high every week and to add 123 grams of spa 100 to raise my alkilinity. So I will not be adding more bromine or shock at this point. So I guess finding out my free bromine is not possible from my dealer.