Thanks for the info Tony! Yep these are the 34" saltwater reef tubes (6500k). Since I already own this setup I go with it.
Have you any lumen info on the 105 watt spiral compact Floros that fit a regular light socket? They're about 12" long and daylight color temp but none of the ebay sellers mention the lumen rating. And I've not seen them in shops yet. I've noticed those 26 W spirals seem really dim.
I always make a reflector out of aluminum flashing in any light hood / setup I build. The angles may not be perfect but it at least helps from loosing that light to the canopy top. Side reflectors (on an empty fish tank or garden area) are awesome helpers too. My Neps colored right up when the foil flaps were added to my tanks.