Wanting to move into HID lighting but cant decide what would be better, a cool tube or a air cooled hood? which would be easier to keep cool?
Cool Tube will be easier to keep cool. You lose some light with Cool Tube design though. Always a trade off.
A cool tube will also takes up less space above itself so you can raise it higher. I got rid of a hood that took up almost a foot of more space then the cool tube and it weighed about 20x more.
When I was growing with HID I went the cool tube route. I particularly liked the ability to integrate it in with my cooling system.