for the cooltube you can either go two routes (that I know work).

1. search ebay for 'bake-a-round' and you will find a ton of them for under $20 shipped. that tube (what i'm using) will fit 400 or 600 hps but not CMH.

2. something called a 'hurricane' lamp shade. I think you can find them at your local hobby store and maybe walmart. This is cheaper and will fit larger bulbs but needs extra modification to hook up to the ducting because it is flared at the ends

here's a link to a tutorial from zandor on this site using option 1:
http://boards.cannabis.com/grow-faqs...cool-tube.html

I didn't follow procedure and kind of just rigged it together with what I had. I took the mounting brackets that come on the socket (they are used to mount the light to the hood) and bent them to wrap around the edges of the tube. I then used foam weather stripping and placed a ring of that around the glass and brackets. Then I put the ducting over it with a clamp and sealed it all together with some aluminum ducting tape and viola
:hippy: