Don't have the fan blowing directly on the plants. Leave fan on at all times. A fan decreases humidity, not promote. See DIY site on making a homemade dehumidifier. Cheap & cool. Is the lights too close to the plants, the hand test works to adjust light. If the lite burns your hand, ... Foliar feeding/watering is OK when in veg stage only. Don't water after the light s are first turned out, this causes humidity build up/ mold. Water an hour or so before the lights come on.Good luck.