I am pulling up a chair and getting all this co2 knowledge I can. I am going to use co2 but I am not going to use a sealed room though. I will have air exchange and I will have to turn off fan for co2. I am not sure how I am going to get that to work yet. I am trying something different with venting with in line fan so I hope it works better then I have before.
Hopefully you have NG in the house, otherwise you might as well add bottle changer to the ol' resume.