What is the best regimine to maintaining a spa with the least amount of harsh chemicals?

My repair guy recommended:
Ozonator + mineral purifier + weekly shocks with renew, then clarifier when needed (He said this would eliminate the need for
ANY bromine)

Already I found this information to be deficient in that my water was too acidic, so I added a buffer.

What are the pros and cons of different regimines?