GrownAtHighAltitude
Well-Known Member
I ran the 400W Phillips retrofits before they discontinued them, and then still after with the GE lamp. The only issue is the GE's are not rated for open enclosure use, so you have to put it behind glass/use fans. The 315 open bulb ends up being a lot brighter. I'm actually in the process of switching everything over to 315's because of the efficiency advantage as well as the actual light produced.