Hey Sprite

"Here's the thing I don't quite understand about temperature: I read everywhere that 75 degrees or so is optimal. I also read that you can put your light real close and as long as your hand doesn't burn after a minute, your plants would be fine. So my hand can withstand temperatures way higher than 75 degrees! This seems like conflicting info--can anyone clarify?"

What they are referring to is the ambient temperature of your room, not the temp directly underneath the lamp. You should be able to withstand the heat of the lamp without burning your skin yes, and I guarantee you the heat coming off the light directly beneath the source is higher than 75 deg. Your Hygrometer, or Thermometer should be mounted just above canopy level in the shade to get a correct ambient temp. Keep a lot of air moving around the closet and get that ambient temp to stay between 72 and 81 deg with the lights on.

Good luck man and keep us posted...