Hey I posted this on another page so I'd thought I'd share with the beginners page too! Adding dry ice to your grow area can not only supply co2for yours plants, but also lower the temperature and raise the humidity as well. Here's a useful link to using dry ice for plants. Hydrofarm - Carbon Dioxide Enrichment Methods If you have any other questions or comments feel free
the cheapest I have found dry ice for is about 1 dollar per pound if you buy 10-50 lbs at a a time. during the life cycle of a 60 day auto flower this will add at least 60$ to your grow. Can't visit my grow every two hours and storing a 60 day supply of dry ice is not feasible for me or most people. dry ice will not work if you are hovering at 60% RH as it will add more humidity to your grow. If you are going to enrich your room with CO2 I would only use option one or two. here is why. 1&2 both require an expensive setup that will have controllers and PPM readers that will allow you to dial in the exact amount of CO2. you will have direct control of how much and when. (Not really ideal for closet growers) 3. temps in your grow will fluctuate, you will never be able to control how fast the dry ice evaporates. so you will have periods where you CO2 is at 1800PPM then towards the end of the dry ice you will only be at you normal 300PPM levels. it is simply not consistent. plus the annoyance of changing ice every day or storing dry ice for an extended period of time. Plus if you already have RH issues it will simply exasperate the problem. 4 & 5. Consistency, I have used these methods (when brewing beer, and the exhale CO2 bags) I have found that there is no way to keep PPM consistent at all, when brewing the amount of CO2 produced greatly differs as the yeast runs it's course you might start with 900PPM at the start but in two weeks as the yeast die you will be down to 300PPM again. The Exhale bags (decomposition) again loose effectiveness over time and your PPM will drop. Plus if you are off and you introduce another bag you can be way over you simply can not control how much CO2 is produced. Not knocking you link or your opinion in any way but there are alot of other things to consider before sinking money into a venture. Another thing to add to the list is ventilation, if your dry ice, fermentation or decomposition methods are employed and your ventilation is pumping that extra CO2 out of the room you are being counter productive, you can not dial up the amount of CO2 emitted from these methods like you can with tanks or burners. Just food for thought. decent link though.