Normal air is something like 400 ppm on average. With a few 1 gallon containers with sugar and brewers yeast in a small 2x4 tent sealed in visqueen I could get roughly another 400 ppms but that was it and it hardly lasted. Brewers yeast is the most active yeast available. Even then it was very short bursts as the yeast was most active with plenty of fresh sugars available. It would taper off after a few hours and slowly deminish. It didn't last. Without regular changings there's no way to keep up an already lacking ppm. Your cfls are the proverbial nail in the coffin though. Additional co2 needs additional photosynthesis to benifit. That's just not going to happen without large lights. There's a ton of myths out there about co2. New growers see big growers doing it and think it's a must have. It's definetly not. Even my buddy says he wouldn't do it if it wasn't for the size of his grow and line of work. He's no small time gardener. If you have a good ventilation set up that brings in a steady supply of fresh cool co2 rich air that's all you need. Learning to grow will benifit your plants more then co2 ever will. Co2 is not an easy set up and quick fix. It takes a controlled environment and lots of planning to work efficiently and be worthwhile. Grow have fun and stop making booze in your grow tent wait till the liquid gets funky smelling
Update: So this has been a learning experience! I'm almost 5 weeks in. I have been trying to train her to bush out. Have a 100% success with topping since the first time I messed up. (The first one actually turned into three tops after I messed up and had to redo it)I'm planning on giving her about 2-3 weeks with nothing but light lst and then switching to veg. Still, have had some temp issues here and there, but for the most part we have been doing well from how I was lol. Still a lot to learn!