Quote Originally Posted by brussels
When using HID's, I always attempt to have 50watt per sqft. <Optimal lighting in every grow publication I've read> Your 16 sq. ft in that case could certainly use 800w. Two 400w lights cost almost as much as one 600w. The 600's are disproportionately expensive for some reason.

I've always liked the 400w lights as you can hang them somewhat closer to your plant canopy, getting the most out of your lighting. Light deminishes very quickly, and every inch helps.

Is it nessary to follow a 50w/sqft rule? No. If going with less light will you have optimal growth and yield? No. It's a lession I've learned with somewhat disappointing yields in the past...B
Just My 2 Cent's.~~~~But I would agree with this set-up. I run 1000w. HID,Those Bitches, Yes They throw awesome lum's, Along with Alot of Heat!!!!!~~~~~~I have to move alot of air just to keep the Grow Room's in the mid-80's, I also use light mover, Sometime's in the middle of Summer, when it 100+ outside, I wish I had A Bunch of 400w.

Good Luck on your decision!!!!