This is my first grow. I've learned enough in the last few weeks to know that they aren't going to turn out as well as they could, but I'd still count it as a success, as it cost me less than $50 total for this one. They were vegged under a 400W MH, and switched to a 1000W HPS a few weeks ago. I ran into major heat problems, and have taken care of them as good as it'll get for this grow. I'll be ordering my 4x8 tent soon, so let me know what you think, and start helping me out with my next grow!
to cool the ducting for your light, Dayton 2C647 Blower 134 CFM 115 V one of these connected to a 12" carbon filter Dayton 2C646 Blower 176 CFM 12 V done, grow giant and enjoy
edit: hah. Didn't see they were tied down. looks pretty good. Might want to try flowering with the 600W. I hear they're much more managable in terms of heat.