I'm such a tool. Somewhere I got the measurement that the light should be 18 to 24 inches. I'm like on the roof at this point. Tonight I saw a chart that suggests that up to 5 inches was ok and actually best. Now I see this thread and I'm wondering why I'm 30+ inches away??? I have an air cooled hood with blower and fans. My temps are always in the 70's and my hood is so cool that I have no fear resting all kinds of stuff on it. Tonight I lowered it to 12" but I think by the end of the day I will put it even closer. According to the chart I read, each inch of distance was 10k lumen loss and at 30 inches, there was practically no light at all. I'm disgusted with myself...no wonder my plants wont grow for shit.

I'm very pleased to learn this information. There can never be too much light...just too much heat. So as long as the heat is kept under control, then I can put the light up the plants azz for all it cares.