Quote Originally Posted by lampost
You must've been looking at the 1000W. Actually a 400W at 18" only gives about 40% of what the sun does if you look at the chart that DutchPimp posted....
I stand corrected lampost. I couldn't see anything in the picture attachment, so I clicked on the link, but didn't notice the distortion in the picture and then numbers are all off!!! so cheers to high times! :jointsmile:

Point being, get as close as you can. I just went downstairs to do a test and I actually got mine down to 12 inches before I really started feelin the heat. Remember too, a fan blowing at the canopy will blow the heat thats concentrated at the top around so it's not so intense, if your temps are stable and you can get cooler air to blow at the tops of the plants, you may even be able to get closer. With a 400w from what I see now its about 7 inches from the top that will be the best.
bcals0087 Reviewed by bcals0087 on . whats hotter? light temps whats hotter HPS or MH in a 400watt ballest. and what is a good distances for high pressure sodiume at 400 watts. and for a metal helide Rating: 5