If the fixture has a common screw-in holder for the bulb, WalMart sells a "Mini Aquarium Bulb, 10 Watt Fluorescent Bulb" made by Lights of America. I find them in the pet section around the aquarium supplies. Over my 2.5 I have this bulb, in an Aqueon Strip Light, 12" long. Actually, the first strip lightI bought was at PetSmart, and I suspect Aqueon bought the manufacturer of those lights, but the Aqueon one I got as a spare is quite similar and I expect it to act the very same way if I start a new 2.5. In my current 2.5 I have java fern, anubias, banana plant (too big... will have to do something with it in the spring), and odds and ends of other plants, even some hair grass. I went through a brown diatom phase on the glass. I wiped some of it away, added a little more liquid fertilizer (Kent's, usually), and basically ignored it. Next time I looked, the glass was all clear. I do give some credit to the red ram snails. Hmm, better go feed them a bit of fish food as a reward since there isn't any algae that I can see... Oh, in the 2.5 I also have a small table-top fountain type pump with the opening covered by filter floss, to keep the water moving, and a small heater since outside currently (Jan 2, 2011, at 10:40, it's 18 degrees F and inside it's 66F).