Youthmananswered grow question 2 years ago Hello! I too have always 70% humidity, not having an extractor I solve by keeping the growbox open (I have no odor or light problems). In your case, try to create a flow that turns the air from the bottom(where the humidity stagnates) upward to vent it out by putting the fan in place. Then keep in mind that during watering, if you have large pots, they will obviously make the 'Rh increase, so you can opt for more frequent watering but with less water :)