The 75 gallon that I picked up also came with a single strip fixture, which was definitely not sufficient. The plants I had in there were dying off because the wattage was just not enough - and we were unable to find any decent bulbs to fit the fixture that would work well for even a low-light setup like ours.
Ended up getting a shop light fixture at Lowes - a lot like this one here:
http://www.lightingdirect.com/light...contoured-reflector/p397905?source=ntg_397905
It holds 2, 32 watt bulbs (we got daylight bulbs at 6700k each), and the difference between that old fixture and this one is phenomenal. The plants are growing back, and the tank looks 300% better. The light fixture sits over the glass top of the tank - the bulbs do not touch the tank - they're a good inch or so away from it, just like they were in the original fixture. We still have the 48" strip that came with it, but not sure what we'll do with it at the moment. Probably storage for now.
I'm still unsure how the guy prior to me used that single bulb to keep his SW tank going. I believe it was a FOWLR setup, but even so, I would have thought it would need more light than what that fixture provided...
In the living room, where this tank is, there is no way to hang the shop light since the ceiling is 15' high, so it has to sit on the tank (unless we can come up with something else). Not sure what your situation is, but hanging a fixture like this may work for you.
