well using a HPS system at 400 watts is to hot and only produces 50,000 lumens for the first 100 hours some at 500 hundred hours and then it can drop as far as
10,000 lumens making it 40,000 lumens my light with 10 bulbs is 39,500 lumens at 420 wattsi think this is all so close that it will not make or brake your yield it is how
you grow also in HPS if you ballast or bulb blow it will cost you i think that has happen to us all you go out of town camping and you get back and the bulb or ballest
has burned out 2 weeks from crop if i loose a light or ballast that is just one and not much of a loss at all which means it is cost effective to maintane i think the heat and customization of the kelvin rating up or
down is the reason i use CFL's that and they kick ass i cant say that putting them around the plant is better then the way i have it set up now taking into
consideration that i have bloomed 14 plants with this light.