The fixture that I am using is an 8 x 54 watt Sfiligoi Stealth. It uses 4 fans that are each ~2" in diameter and are mounted at the left most end of the fixture, just behind the endcaps. In this way, one fans blows along the length of a pair of bulbs. The fans are also wired to a variable voltage DC converter so that depending on the temperature of your house, you can run the fans at anywhere from 3V to 12V in order to have greater control over the temperature inside of the fixture.
I took some before shots of the tank but it is hard to capture the acutal light intensity. Once I finish swapping bulbs and setting the fans to the correct voltage, I'll snap an after pic and see if I can notice a difference. Most likely, it will be negligible without the aid of a PAR meter, but here's to hoping
