So basically what you both are saying is yes they work but not cost effective. With the Exhale you need more bags and you have no control of out put of co2 .
@Dynamo626 you said the Enhance works and puts out more co2 than the Exhale but only last a week.
So if they both produce co2 (which the plants love) and I run autos and run lighting 24/0 wouldn't my plants benefit from the added co2? I see where the Enhance would be costly to use on the other hand the Exhale bag is a hang and work deal and does supply co2 just need 4 in 4 x 4 area.
Cannabis doesn't use CO2 when there's no light.
Like nearly all plants, marijuana stops using CO2 during the night (dark period). CO2 is primarily used in the day by the plant as part of photosynthesis (turning light into energy), so if there's no light, there's little need for CO2.
Therefore, flooding your grow area with CO2 during your dark period can be a waste of time and money. CO2 mainly provides benefits when the lights are on.
I'm just trying to understand all this. IMO it does seem plants would need more co2 when supplying more light especially autos where you have the option of running a 24/0 lighting. Just a newbie trying to craft his skills with Autos and looking at all the pros and cons of adding co2 to my grows. Thx