We are reasonably new owners of a 15500 gal fiberglass pool, and a 550 gal hot tub spa. Been using the BBB method on the pool all summer to great results. We are considering switching the spa over to BBB instead of bromine. The spa is a bit smelly and feels itchy when we get out. Can anyone offer some advice on the pros and cons of using the BBB method on a spa? And at what FC, Ph, and TA levels are optimal?