That's my question, in theory 250watt + 400watt is the same as a 600watt just in two lights instead of one. The spectrum should all be there. The way Im running two lights in such a tight space is they fit. Im a carpenter and I built the room, so I can pretty much fab shit up the way I want and I got a gang of fans to keep it cool. The temp stays around 70-80 degrees and humidity stays around 50-60%. My question is 250 + 400 = 650 thats 50 more than a single 600, but just because theres two light instead of one that doesnt mean anything but a little more heat? The spectrum is the same right?