Welcome to our forum.
To me this is like having sex without protection and relying on the "rhythm method" to avoid pregnancy. It may work sometimes but...
I am not quite as brave as your friend, Gomboman. However, I have a 97 HS Sovreign with an ozonator and here is my routine.1. Fill, check Ph, Alk, Hardness and adjust if necessary.2. Drop a new Nature 2 Cartridge in my center filter standpipe (the one feeding the 24/7 circ. pump)3. Once a week add 2 1/2 to 3 Tbsp of Spa Guard Enhanced Shock.4. Once a week, check Ph and Alk and adjust if necessary.5. Once a month, clean filters (sometimes just rinse)5. At 4 mos. Drain, Clean, refill and install a new Nature 2 cartridge at that time.I do not add dichlor after each use. The only time I've had a water issue was this past week when I didn't rinse all the filter cleaner out of my filters, but a dose of shock cleared that up.I'm a firm believer in ozone and the nature2 for that matter. I'm convinced that working together, they have reduced my time spent maintaining my water and given me more time to actually enjoy it. It makes me all the more thankful when I read some of the posts where people are adding something or doing something to their water daily to try to "fix" it. If I had as much trouble as some I've read on the board, I would give up on my hot tub. Isn't the whole idea of one to help you RELAX?
I've known more girls who got pregnant on the pill, IUD, even after tubals and vassectomies than I do who got pregnant from NFM.
You can't count porn stars!
Ozone is an oxidizer first and a sanitizer second. It will try and oxidize any metals or particles in the water before it tries to act as a sanitizer. The only way to properly sanitize a spa (using chlorine) is to get the chlorine levle to 3-5ppm. Period.