I wish I would have stumbled across this about $500 ago. We bought a home two year ago that came with a very nice Jacuzzi spa. Learning to deal with spa chemistry had a slight learning curve, but wasn't too hard. I use bromine as the sanitizer and a mineral stick as well to help save a bit on bromine. It's worked fine, but the thing that really irritates me is all the money I have been shelling out for spa/hot tub chemicals.
I happened upon this website a few weeks ago about using what is called the BBB Method for pool and spa care. BBB, Bleach, Baking soda, & Borax. Bleach is the sanitizer, Baking soda increases the PH and Borax adjusts the alkalinity. I am very interested in giving this a shot. Right now, I want to use up the chemicals I currently have. We usually drain the hot tub during the winter... so it probably won't be until next spring before I try the BBB Method on my spa. I'm sure there will be a learning curve with this too, but cheaper chemicals makes it very appealing.