lordsoth : i use a 400 watt hps agromax bulb with 30% blue spectrum
this is the first grow that i used it on and it seems to work great, if you notice on one of my plants all of the lower branches caught up to the center stalk i beleive the specific bulb i am using excelled the growth of these lower braches. i plan to use the bulb for veg and flowering good luck in your grow peace