We got similar advice from the dealer as other posters: MPS after every use and dichlor once a week. We have a Jacuzzi 470 with the corona discharge ozonator.
After only one week, we had cloudy water- I had been testing every day but forgot to test that morning and we soaked that night. Unfortunately we didn't realize the condition of the water till we'd been soaking in at for at least 20 minutes because it was full dark outside. It had been at least 24 hrs since we had put any MPS in and since it was less than a week old, we had only added the original double dose of dichlor suggested by our dealer and none since.
I came up with a lovely case of hot tub rash within a day of discovering the water had gone over.
Needless to say, we drained the tub and started over with dichlor. I went over a ton of posts and gleaned a lot of info from this and other boards. Hopefully we're now on the right track with 1.5 tsp of dichlor after each soak, and shocking with MPS once a week. The water has been crystal clear for the past week, and I test daily because I'm now super paranoid about the water going bad. Especially since we have our kids in there every few days- I'd hate for them to get the rash I have (which I"m wishing would heal up soon so I can go back to soaking!)