is the cool tube you are talking about a bake around? The cool tube i have, and most that i have seen are about 22'' give or take a few, that should fit. but if you dont want to spend the money a DIY is a simple and fun project. Isnt it funny how everyone raves about how cool cfl's run, but when you actually use them they are hot. i had 4 42 watters and my box was over 109. I cant imagine how you could keep good temps without a cool tube on any HID. so too me it is a must! as im sure you have figured out. good luck and start a journal!
best of luck
