ok well I have been thinking and I know that CO2 sinks so I think that if it is outside of a bottle like that.. it would probably rise out (like out of the bucket I have) and then sink onto the floor most likely.. which right now doesn't help me, but once I transplant all of my plants that are in party cups now, I will be putting them all on the ground anyways so that would be fine..
but anyways, I found a 5 gallon bucket that I had used to hold eels while fishing last summer but anyways I didn't find a top for it, so I just used 2 cups of sugar and a packet of yeast put them in the bucket like I said with a little epsom salts and a few drops of ferts.. put a plastic garbage bag over the top, with the air tube going under it, and taped it around the top of the bucket tightly. and poked 2 small holes in the top corners (bottom corners really of the garbage bag) so the CO2 and excess air from the bubbler can get out.. and this way the yeast can't really contaminate anything else which I don't think they would be if there is anything else growing in there.. it won't spread either
also I was looking online because I know that fermentation is really inefficient and remember/found that yeast can still do cellular respiration when there is oxygen.. which means that it will produce more CO2 per molecule of glucose... so I was looking around for an air stone, but didn't have one so I just used a aquarium bubbler that I had for my fish tank which I have no fish in right now and plugged it into the outlet where my fan is hooked up to.. so that it will turn on when the fan turns on, (I have it set to come on like every other hour for 10-15min or something like that) so that they will make more CO2.. already the basement smells like yeast because I vent the grow tent with my exhaust fan because it was getting too humid in there.. so I vent it out 3 times a day set on a timer for about 20-30min to get all the excess moisture out once it builds up a lot.. it also keeps any puddles forming on the floors from all the moisture and really helps a ton with the edema problem I had
so anyways I will see how this works out over the next week or more.. see if it makes any noticeable difference.. if anything, more CO2 can't be a bad thing.. so it can only make things better I would think
here is a quick/random link of the difference in cellular respiration-
http://www.purchon.com/chemistry/chemical.htm