These are the 3" baffles, center chamber which can also be used as a refugium, and the return pump section. I asked for the 3" spacing between baffles, so I could add the filter foam for more mechanical filtration. First 2 baffles have 15ppi foam blocks, In the center (fuge), is ceramic bio media that came from the 2 fluval FX5's on my old 125g tank. The last 2 baffles have 30ppi foam. I also currently have all the filter pads from the FX5's as well, to help seed the new tank. It's been about a week and a half now, and ammonia is still undetectable.
The return pump chamber houses a Rio 1100 needle wheel, which is where I'm injecting my CO2. The mist is being returned to the tank via the return pump, which is an Aqueon AQ8000 (2113gph @ 0 head).
I mentioned earlier that I don't really like the mist blowing around the tank, so I'll be plumbing in a cerges dwell time reactor in the near future (once the filter housing arrives in the mail).