I have some questions about ventilation. Maybe you guys can clear things up. The reason ventilation is necessary is twofold, as far as I can tell. The first is to keep a constant supply of fresh CO2 to your plants and second to keep the heat from building up in the grow chamber. Are there any other reasons? Assuming no, how well would the following configuration work? An enclosed grow chamber, not airtight, but no explicit vent or fan. A moderate CO2 source, replenished daily (or every other day) and the entire chamber vented at CO2 change time. This would help keep the odor down and eliminate the need for some complexity in the design. The drawback, of course, being the need for constant CO2 replenishment. I'm looking at doing a micro grow, one or two plants tops, and it needs to be super stealthy. The rate of CO2 consumption for two plants couldn't more than the amount of CO2 produced from 2-4 liters of fresh sugar/yeast solution each day. If the box stays sealed the CO2 would accumulate early in the day and decrease as the plant used it up returning to a baseline atmospheric level some time later. Anyone have any experience with anything even remotely similar this? How'd it go?