I had a 6 gallon eclipse running for almost 2 years. It worked great for me... until everything grew so much that the more aggresive species were killing off its neighbors. So, I've upgraded to a 20L.
In anycase, for the Eclipse, I removed the factory biowheel and pump system. (It gets in the way of the lighting and doesn't help anything in the tank). Then, I removed the light.
In the beginning, I got 3-13W PC lights and screwed the sockets onto little pieces of plexiglass, which, in turn got attached to the hood. Then, I added a CPR bakpak, that I used as a pseudo refugium, I threw some calerpa in it.
It worked great! I didn't have any fish, so I rarely fed it. Lots of lights. It was really beautiful!
I still have the Bakpak if you need a skimmer... Be warned, it sits higher than the tank, so you have to do some creative balancing to get it stationary, but it was awesome for the water quality!
Email me if you have any questions.
Good luck!
achu