MyCO2 Mushroom Bag - Bloom MyCO2 – Mycelium Derived Carbon Dioxide are CO2 bags perfected. Unlike all the other CO2 bags that "come cultivating CO2 even before you get out of the checkout line," MyCO2 has the patent pending customer activation technology, postponing the CO2 cultivation until you get it home and are ready to use it. One CO2 bag provides enough carbon dioxide for flowering plants in a 4ft x 4ft grow tent with cycled exhaust. Use during the flowering stage. We recommend safely placing multiple MyCO2 generators above the highest level of your plants to insure they receive the CO2 as it is generated.