There are a lot of different ways to degas water, that isn't the issue I have. In my particular case it will be inline with my plumbing, as the final step before it returns to the display. Since it will be enclosed, I need to facilitate the gas exchange, either by introducing air in at the bottom or removing it via vacuum though the top. This way water flows down through the media and is broken apart, as air flows up and strips off CO2 and other gases from the water. I probably won't be using a venturi in this case, as I'm not sure it will be as efficient.
Finding the proper air:water ratio is what I was unsure about and prompted the thread. Most of the info I find about degassing takes me to articles & journals on Science Direct, which I would have to pay for to read. The limited other info I find has 2:1, 5:1 and even as high as 20:1. I know a lot of this application specific and I also know there is some math involved in figuring it all out, which I haven't found. With Matt's background, if he seems to think 2:1 is plenty (maybe even 1:1 would work), then I'm probably on the right track.