Looking great! Have you considered a cool tube style fixture, with the HID bulb inside a quartz glass tube? I have one like that for my 600 and it gets rid of a ton of heat. Its hard to tell in your pix but I can't see an enclosing tube? They do sap a little light, although the uv yellowed my test piece of newspaper easily so it's getting through. And your bulb won't explode if it gets hit with a single drop of water, as spectacular as that is! Last run I kept it about 18 inches from the plants along with a 200 watt cob, and it all performed great! I'm trying all led this run to reduce the ventilation requirements, but the HID 600 is like an old sweater!