Kinetic, is the Marina 7w one kind of a silver round thing that rests on the tank lid? Like this?
If so, then NO. It melted the plastic lid on my tank. Get LED if at all possible. Penn Plax has a new small LED light fixture out, see if you can find something about that.
EDIT: Tiki, the plastic switch thingie, can it be removed? If so, stick it back in and adjust it. It's there to keep the filter level. It kind of props the bottom half of the filter out.
EDIT II: Ditch the carbon. Fishy's right, it removes plant ferts and stuff.
EDIT III: Kinetic, this is the Penn Plax one I'm talking about on amazon.