Supplementing with co2 is for the advanced grower. The plants don't benefit significantly unless temperatures are kept high. But growmaxx is right about the air circulation. You want a fan of some sort to extract the air. Passive extraction as you are considering may work on some level but ideally you exchanged the air regularly. Let us know what you end up doing!
bigsby Reviewed by bigsby on . Venting your grow room..Good/Bad idea? Ok this is an idea im planning on putting into action for my grow. The grow room will be 5ft x 5ft x 6ft, frame made with 2in x 2in wood, and then wrapped in chicken wire for support. Then heavy black sheeting wrapped all around the outside to stop light, and the inside will be covered by 5 safety blankets(100% mylar). Now this is where your imagination has to be utilised....- approximatly 10 1ft(or half a foot) plastic pipes( 2in diameter ), these will be placed around the grow room top Rating: 5