I have an LED cabinet grow with 4" inline fan and matching filter exhausting to the outside through an unused dryer vent. I bought everything off ebay. I control the speed with a router controller. Problem is I can still smell it outside. Faint but still there. I searched and thinking I should dial down the speed. Currently about 45% speed. Should I keep dialing it down until there's a heat problem? I'm in day 40 of bloom and she's getting stinky!