What Size Do You Like for Reef Sump in 4x2x2 tank Stand?

[Captainhemo]

I had similar experiences here. Built my stand way before I had even considered a sump, in the end I had to remove parts of the stand to fit the biggest sump I posibly could.
Try and buy your equipment before building a sump, that way you can custom fit everything as needed. There is no point having a huge skimmer area if you end up with a skimmer with a small footprint, on the other had, if you end up having a larger skimmer, you'll want to make sure you have enough room to fit it in. When you are selecting a skimmer, be sure you have enough vertical clearance in the stand to be able to easily remove the collection cup for cleaning, this was a really big issue for me as there wasn't alot of vertical space inside my stand.. Alot of skimmers are 20"+ and then need a bit more for the removal of the cup, just something to watch for.
As mentiioned a in an earlier post, make your return section as large as possible if you aren't going to be using an ATO. As the rest of the sumps water levels are maintained by baffles or dividers, any evap will cause the water level in the return section to drop, you don't want the pump cavatating/sucking air as water in the system evaporates. I lose about a gallon / day.
You'll also want to leave space for any heaters/probes/ phosban reactors etc etc, lots to consider .
A good site to start at is:
here
HTH