Here is a necessity invention that is working beautifully. Explanation: The carbon filter ($8 from anywhere) is tied to the fan and then when it runs on low it will remove all- and I mean all- cannabis smell from the room within an hour. It might require full-time running soon, because that shrub is getting ready to bloom. It says it's good for three months, haha. Working class odor control for when it is needed. I just wish it was all in a nice grow tent with inline ventilation and filtration, but that may happen soon too!