[stevedola]

I would not advise lighting a 4 ft reef with a 3 ft light. I think you'll be limiting the corals you can keep. It may not look dim however it will not look as bright as the 4ft fixture. I have a 4ft- 6 bulb on a 90g and a 2ft 8 bulb on my cube...great coverage, great par, great everything. I know you want a canopy but in my opinion these lights do an excellent job of focusing the light into the tank and look sleek doing it. My lights are 3-4" off the surface and I have very little light spillage.

Can a reef be lit lacking 6" on either side? of course, I wouldnt advise it if I had a choice between the 2 sizes.