I had a question on my ozone setup and use. I've posted this before so most of this will be a copy paste.
You certainly don't need much ozone to produce results. I've also found very small amounts to help skimmer production while higher amounts hinder a good dense foam production. Some people will only run ozone for a couple hours right after lights on with great results.
I have used a 50mg/l redsea aquazone for years and have it down to running 25% for around 200 gallon system volume. That is a very small amount and poses little risk to fish even if GAC wasn't used. I do have a bag of GAC (ROX 0.8) sitting in front of my skimmer's output as a precaution. I do feel it acts like a flocculant at that small amount along with being an oxidizing agent. As others have said it's only one small part to maintaining my system.
More importantly though is that ozone isn't released into the atmosphere for you or anyone else in the house to breath in. (another reason I like very small amounts.) If using a skimmer as a reactor put bags of carbon over the collection cup if there's holes. I used to tape the holes up with duct tape except one of them and shoved my skimmer's airline in it to draw in any excess ozone air back into the skimmer. Lifereef skimmer do this already. My current skimmer is sealed on top with no holes so I don't have to worry about that part (MTC MVX).
Waterkeeper pointed me to these articles a few moons ago and should be read by anyone looking to use ozone.
Ozone and the Reef Aquarium by Randy Holmes-Farley Parts 1, 2, and 3
http://reefkeeping.com/issues/2006-03/rhf/index.php
http://www.reefkeeping.com/issues/2006-04/rhf/index.php
http://reefkeeping.com/issues/2006-05/rhf/index.php
Posted this just recently but shows how I used to duct tape the holes on top except one to suck back into the skimmer any unused ozone.
The MTC MVX is sealed with a rubber gasket and screwed down. No holes on top.
Now for how I have it all setup airline wise.
I use a T to split off and control freshair flow and airflow from the ozone generator. And you'll see I also use a CO2 scrubber pre ozone generator.
The sodalime CO2 scrubber actually does two things for me. It acts to reduce CO2 going into the skimmer which helps elevate my tanks pH slightly but it also drys the air some as well which makes the ozone generator more efficient.
I T off the air flow going through both the CO2 scrubber and ozone generator as the generator doesn't need that much flow and would actually restrict airflow if I didn't T off and restricting the air flow through the scrubber increases its life as the sodalime would be exhausted much faster if pulling 100% of the air draw through it and I found it doesn't help increase pH that much more doing so.
So
Air in > scrubber > generator > T > skimmer
Air in > T > skimmer.
If that wasn't confusing here's a picture of the airlines which may or may not help clear that up. And you'll love my way of connecting some of these hoses...shoving one into another. Im not concerned with airtight as the air flow through the generator is less then the total airflow.
Air in
Sceubber to generator
Generator to T
Air in to T and T to skimmer
And my ozone generator is controlled by my apex. Monitoring orp should be done when using ozone.
Fallback OFF
If DT_ORP < 400 Then ON
If DT_ORP > 425 Then OFF
If Outlet skimmer_7_5 = OFF Then OFF
