Ozonizers have come a long way. It used to be essential to run the effluent of your protein skimmer (where you typically injected the ozone) through carbon to remove all the excess. Now with today's technology, and ozonizers with built-in controllers, the average aquarist can safely take advantage of ozone.
How does ozone work? In a nutshell ozone is fed into your protein
skimmer where it will break apart large proteins etc. that your skimmer can't take out (they won't attach to bubbles). This makes your protein skimmer more efficient, and your water clearer. Many people don't
even run carbon when using ozone.
It is highly recommend that when employing the use of ozone that you do so in conjunction with a controller. This will ensure that you are not adding too much into your aquarium - there does come a point when not all of the ozone is being utilized and the excess will enter your aquarium (which is bad!).
We at J&L Aquatics do feel that now, it is safe for the majority of the "non-techy" aquarists out there to enjoy the benefits of ozone without worrying about it's side effects!