I am trying out adding CO2 to my grow room for the first time. I currently have an AC unit venting out of the room and a carbon air filter that does not vent out but just is running 100% of the time and just blowing back into the room. If I am going to be adding CO2 to the room I know I need to have the AC unit be off during times when i am blowing CO2 into the room or it will vent out the CO2, but what about the carbon air filter? It does not vent out of the room just blows back into the room, will this hurt or harm the CO2 in any way? I found this calculator: CO2 Calculator - Greentrees Hydroponics and it says for my size room (800 cubic feet) that if i set the regulator to 4 CFH that it should fill my room in 15 minutes... does this sound right? My thinking is that I want to fill the room once every 2 or 3 hours and then just let the AC run for 30 minutes at the end of each cycle. So basically run the CO2 at 4 CFH for 15 minutes then let the room chill for 1:30 or 2:30 and then for the last 30 minutes run the AC then repeat. Sound good? I am especially curious about wether or not the carbon air filter will negatively affect the CO2 emission. Any advice about these questions or just general advice about CO2 would be greatly appreciated. Thanks in advance.