I just finished (well almost finished) an unfortunately sized sump. It was to have as much of it viewable as possible so I wanted to have most of the front of the tank as a fuge.
The sump is 48"W X 16"D X 24.5" High. NOT an ideal sump size. (height and depth aren't great) - 75-80 gallonish.
I'll try and post some pictures later but it is basically like Melev's large sump.
(
http://www.melevsreef.com/acrylics/s.../80g_sump.html) - his 80 gallon sump.
So in the first pic you'll see the drain section and on the right you have the fuge. The return section is in the back. The only thing different on mine is that the water flows from the fuge back into the bubble trap between the drain/skimmer section and the fuge.
This allows me to have a really really tall fuge section (full height of the tank) and then have it fall into the 12" high skimmer/ return section. I couldn't make the skimmer/drain section too high because of the operational high for skimmers and that I have a height limitation in my stand (as we all do). I'll have to use a stand for my skimmer.
Once again. so water volumes for me are roughly:
40 gallon fuge section
6 gallon return section
11 gallon skimmer/drain section
This is for a 90 gallon tank.