i never have the faqn blowing directly on my plants. point the fan in a corner, a little sideways and a little up. it creates a big swirl around the room. if your leaves are just barely moving, thats plenty of air circulation. it will help control powdery mildew and also strengthen the stems. if you have a dense canopy, make sure your fans in a position to circulate the air down low, into, bewlow and around your canopy.
if your plants are in a closet space and not an open room, crack the closet door and put the fan OUTSIDE of the closet, blowing gently from across the room in the direction of the door. you dont need the fan blowing directly on your plants. all you need is just enough air circulation to see the leaves barely move, thats enough to circulate the air. also, remeber if your growng with MH or HPS lights ( or any other HID system) that you ca actually make heat problems WORSE in your rom by running a fan. a metal halide lights put out as much or more heat than an electric heater,if you have several, your asking to cook your plants without proper ventilation. when the air passes around the lighting, it recirculates the heat put out by the bulbs instead of hanging around them and the ceiling down lower in the room at plant level. bad news.
i also run my fans on a timer, hour on, 2 off.
was high when put the timer haha
