I drained my 7500Gallon spa, filled it back up, and got my levels to [7.2 PH, 60 Hardness, 120 Alk, 0 FC, 0 CYA]
I'm going to use bromine instead of chlorine. So I poured 30Oz of Sodium Bromide to make the reserve, then poured 2lbs of MPS. I waited an hour. BR/FC raised to 6. I had wanted to...