Oh, the ozone debate lives on! Ozone only "lives" for a few seconds in saltwater prior to breaking down to more stable oxygen. That's why you'll unlikely detect it in your water. During that time, it can, however, react with other elements to produce ozone produced oxidants which have longer lifes. One such oxidizer is a bromine compound which, in high concentration, can be bad, and that is what the carbon is really for. However, in low levels, you won't generate enough bromine oxides that can't be biologically broken down. Check out the reef chemistry forum if you want to learn more.
I've dosed in the past, like Michael, with no carbon and no ill effects. However, to be effective, you need a large surface area to volume ratio and a long dwell time, and that's why people typically inject it into a skimmer or ozone reactor.
Dave
