since plants can absorb seven times the amount of co2 thats currently in the air, any amount over normal makes a difference, sure it might not be a measurable difference to our eyes, but a difference never the less.It doesn't contain enough to make a difference.
yeah, its much easier than that to just spend as much time as possible in your growroom.I'm not saying that there's not enough CO2. Just not enough in that little container for it to be worth hooking up. He would need to fill it everyday.