Welcome to our forum.
No direct relationship between bubbles and ozone.A couple of other things. There is an ozone injector procedure. Check your owners manual. Also, check your circ pump filter, the one with the grey stand pipe. If clogged, it will restrict flow.
Vinny,No, I have not changed the water yet.What is a CD unit? Is there an indicator light or something on the display that would let me know?Thanks!BearBath