So I have been thinking bout getting a moonlight for my 55, just wondering what other people use, how many LEDs, wattage, or whatever other important info for Moonlights...
Here is a link to directions that I followed and it worked beautifully. Here is a link to directions that I made for a 55g. As you see in the second link, I used 8 LED's, 4 on each side.
You could also try cold cathode lights, directions found here. I have 2 sets (2 reds, 2 blues) in my 72g and am quite happy with them, although I will admit that over time one does shine brighter.
I just dremeled two holes in the hood for each individual bulb, and a small piece of double sided foam tape on the unit and stuck it. I have one unit on each tank(one white and one blue), the white is fantastic.