Someone can light a joint and it can stink up an entire block – this might seem exaggerated, but how many times have you walked down a place – seemingly with no one in the area except the lingering trail of marijuana smoke? This means that you would have to neutralize the terpenes in the air around the grow. For outdoor grows this is nearly impossible unless you have it in a greenhouse – which is quite likely. In that case, there are a series of “Terpene-Neutralizing” technologies out there.