I’m in the same boat. You have to look at what they’re doing to. Sealed rooms with a/c and usually a double ended gavita per 4x4. Those bags barely raise the co2 level as it is, then you have to keep it in the grow to be effective. Then you have the lighting to drive that kind of photosynthesis.
Every grow is a little different, but having bigger plants could be for a lot of reasons. Look around some, there’s lots of members growing huge colas and have outstanding yields on ambient co2.
If you are exhausting air to the outside, don’t bother with CO2. You are not generating enough to change the level in your room. At best, with a sealed room, AC, and enough light, your plants will just grow a little faster. It’s easier and a lot cheaper just the let them grow a week or two longer.
If you have a sealed greenhouse with AC and humidity control, and want to get as many grows as you can per year, it might make sense. The determining factor may be money: Are you trying to make a lot of money, or do you just want to grow some weed to smoke? In California, the choice is easy. Grow six plants and stay legal with no licenses, police, or zoning hassles.
In a different thread, more interesting info on co2 in the middle of the post. Specifically, my idea of turning the fans off at night so it can accumulate is officially a non-starter…
I agree! There are sooo many other limiting factors you can cost effectively deal with before even considering CO2 levels. Its a non starter IMO…
So the bottom line is it probably doesn’t help any unless you have the right lights, a sealed room, and a pretty large ppm of co2 @Skeeter19_5. It won’t hurt anything either they way we are doing it now. I stopped using it the last 2 grows, but started again this time to see if I can tell any difference.
Yeah that is what I got from it.
Unfortunately from what I heard they don’t take in co2 when lights are off, I might be wrong but thought I read that somewhere. First time using the bag of co2 and I do notice a big difference in the size of the tops on this grow. Time will tell, if my bud sizes are larger on this grow I am going to attribute it to the co2 because it is the only thing I am doing different. Learning process. I should fork out the money and buy a co2 tester. Also my system is a sealed system, no vents are open. I have a filtered intake and filtered exhaust that runs 24 hrs, the circulating fans go off when lights go off.
Yeah, I got that part. That is why I posted the link to the other page. Is there also a possibility that you are a better grower this time, and it’s not the CO2? I mean if it works for you rock on! I just see it as the TAG body spray of weed-growing. It never does what it advertises, but the kids keep buying it anyway 
Well I know for a fact the bags are putting out co2, it is a matter of is the plant taking it in or is it getting sucked out of the grow room by the exhaust fan before any of it is absorbed by the plant. Heck I am willing to try anything, I am twisting and turning branches, breaking them, doing things different and seeing what the out come is. Read an article that said you want to make your plant grow like a table top, horizontally, so I been tinkering around with that and have double the tops I ever had.
I think that your personal comfort with the growing process, and doing the things quoted are what boosted your yield Like I said before, I don’t think it’ll hurt, I just think it’s not helping that much either.
Well I’ll find out if it don’t work I won’t do it again but it’s probably just a gimmick to make money just like everything else. I look at all the fertilizers with all of the fancy colors and pictures of gigantic Buds and frogs and all kinds of crap on the bottles to make them enticing to buy. The guy at the store was trying to get me to buy Bud Candy and I looked at the ingredients and it was magnesium. Well my Cal Mag has magnesium in it so why would I buy more.
That is my train of thought, hence the Tag Body Spray reference (never got me any girls 
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I don’t think it can hurt I just don’t think, for me or you, we could produce enough co2 for it to matter unless we had a tank and a sensor/flow-regulator to keep it at a high level. And then I couldn’t look at them as often as I do!
I agree on the nute-labels too! To be honest, I got the FF line because they had a deal on a pack that had everything I needed, and they had a easy-ish schedule to follow. I also read an article about the 4 stages of flower, and the granules that are specific to different stages of flower seemed to agree with that. We’ll see.
If you have any kind of exhaust fan running, you would have to generate a huge amount of CO2 to keep the concentration up. People successfully using CO2 have sealed room with air conditioners to keep them cool, and very bright lights. Even then, all the CO2 does is makes the plant grow faster. You can probably see the same benefit by vegging another week or two. So I think it only makes sense if you have a commercial greenhouse.