Just wondering, does the chlorine calculator work the same if using bromine in my spa? I would like to use the 12.5% chlorine that I use in my pool to oxidize the bromine in my spa, but I wasnt sure that if the calculator tells me X amount will raise free chlorine by Y, that Y would translate over to free bromine. Or do I multiply Y by 2.25 to get the the new bromine reading?

Thanks guys!

The bromine reading is 2.25 times the chlorine reading. So just divide your current and desired bromine readings by 2.25 to enter the equivalent FC numbers into The Pool Calculator. Likewise, when seeing the effects of adding chemicals so getting an FC amount, multiply by 2.25 to see the equivalent bromine level.

Thanks for the clarification! Happy long weekend!