CO2 bags...DO they work ?

I am wondering if these co2 bags they have out there for $30 to $40 bucks that just sit on a shelf really work ??? I am doing the brewers yeast and sugar water fermentation method right now to try to create some co2 but not sure if that really works or not....any help would be great... thanks

i have not used them personally but i have heard they work good, more-so in smaller spaces with less plants. It would be awesome to see someone do a control experiment. I'm not sure if im wrong but i dont imagine much of the co2 being absorbed by the plant(s) if there is a high amount of ventilation/air movement going on all the time. Some people use tons of fans.

co is a waste of time unless ur gonna go with a sealed climate controled room entirely. i messed
with sugar/yeast bottles and tubes for a time and cant say they werent benificial, cant say they were either
not worth the trouble but then im organic and became lazy with my spare time from not messing with
bottled nuets,ph etc