So I bought the house in May and it had an in-ground pool and a separate hot tub. Im familiar with TBT so I quickly took over the pool. In regards to the hot tub I was just adding bromine weekly (I have ignored the spa Never used, never paid attention). Now im ready to clean (with Ahhsome), drain and refill. Since this is an old spa with no UV or Ozone, can I convert to Chlorine or should I keep it running Bromine? I read both pinned articles and I am stuck. What would you do? Also what is the best way to calculate spa volume? I have no clue on make/model