Bucky, my wife has RA and she takes medication to lower her immune system. So the ozonator is an additional safeguard so she can enjoy the therapy of the hot tub safely. Isaak, I replace the tubes every 6 months.
I just wish I could find a more reliable, longer lasting check valve. Spending $100 when a $5 part fails get's old fast. I even go to the trouble of making sure there is a complete loop of tubing above the water line.