All right i'm using 1 400watt metal halide and 1 400 watt hps at the same time. i'm trying to get a full spectrum. is it better to use just mh or just hps. i've also heard mh for veg and hps for bud is this a good idea? i've 1 more of each type of light so i could set them up if ya'll think its a good idea. 6 plants in a 4' 1\2" X 4' 1/2" room lined with mylar any help would be great!
full spectrum is best dude.. at your roomsize (16+ square feet) and if you want the optimal 50w per square foot (16*50=800w) two lamps would be perfect. On the other hand, you could save energy/money if you could trade in the 4 400w lamps for 2 800w/1000w lamps and get a light mover, this would allow you to cover a large area with a single lamp. During the flowering phase especially, a larger wattage lamp will give more bud, which is what everyone wants
http://www.altgarden.com/site/lightmovers/page1.html just the way it sounds.. moves your lamp very slowly across a room and back