Yep, just as with halides, Ballast + reflectors determine the output.
I don't buy the whole cooling thing with the T5's.
When I made my decision between the
ATI powermodule and Sunpower I really couldn't find a difference that would make one brighter than the other. Only real difference was one extra cooling fan in the powermodule. How can this one fan make the bulbs produce more light?
This is the description of the sunpower
"T5 high-output fluorescent lighting system complete with individual parabolic reflectors for each bulb made from silver-coated 98% reflective German-made aluminum, built-in electronic ballasts, active cooling system, acrylic shield, two 10 ft power-cords and sleek, adjustable hanging kit to suspend the unit. Superior design and high-end components produce 50% more light than most other equally sized T5 fixtures without using more energy. Fixture is wired with 2 bulbs on one power-cord and the other 4 bulbs on the other allowing for independent control and dawn-dusk simulation. Silver colored, bent aluminum body is lightweight and rust-proof. Runs very cool and produces virtually no noise. The SunPower is a more economical version of the ATI Powermodule with a bent aluminum housing instead of a curved, heavy-duty steel housing. It also has one fewer cooling fan.
Performance wise the SunPower is almost, but not quite as good as the Powermodule. Common Sizing Guideline: mixed reef tanks up to 50 gallons and SPS dominated tanks up to 40 gallons. Recommend Tank Depth: up to 30" with carefully planned placement of corals. Power Consumption: approximately 1.5 Amps. Warranty: 1 year. Bulbs sold separately."
Looking at this It would make sense to go with the sunpower and save some money. My decision was to go with the powermodule because after all the purpose of most of our tanks is to make a nice display. I like the looks of the powermodule better
This is comparing Mercedes to a BMW though. After seeing a few of the budget T5 lighting systems and comparing it to a high end T5 system it's night and day. The T5's from a current nova fixture look
VERY dim compared to the powermodule.