This sounds like a great idea! Since I've rescaped, I can't position my powerhead (w/ quickfilter attachment) where I'd like. And even if I could, the "misting" is not as even as I'd like. There's definitely an advantage to CO2 misting, as shown by plants in certain parts of the tank, where the CO2 hits the bottom and rises up through the plants, but the opposite end, plant growth is well, meh...

What I'm looking for is a filter to serve mainly as a mechanical filter that has enough oomph to drive a 40-45" spraybar, as well as serve as a diffusor (direct CO2 injection). I'm thinking maybe a Marineland 350 cannister? I don't want to spend too much. I'd go with a powerhead, but they are bulky, and I need the mechanical filtration, as my Eheim 2028 can't keep the tank as clean as I'd like all on its own.