Oh I hear your pain! I don't have (can't afford yet) anything fancy like in-line vents or temp/humidity control anything... Working with nothing but a tent, a light, a dehumdifier (small) and an oscillating fan, I've tried this and that and what works for ME is opening a bottom side vent and leaving about 2 feet of the zipper unzipped. Yeah, it lets light out but at least temp and humidity are finally under control... better that than the reverse, imho!