Hello all, Have done extensive reading from this as well as other sites and have learned an ass load of awesome information...thanks. I have a couple of questions that I can't seem to find agreeing answers to. My question is regarding co2 levels in a sealed room..well almost sealed. A room that is entirely sealed except for the window ac unit as it needs exhaust to cool properly. Will co2 be needed, or will opening the door say twice a day and the exhaust be enough? Do these DIY co2 generators work ie yeast sugar mixtures effectively? Any input on this setup would be appreciated.. Thank you.