I've found that a fuge works best if the turnover is quite low (less than 10 times the volume per hour) and if you feed it dirty water (straight from the tank is the dirtiest). Each sump is different and there are many ways to plumb it but a lot of people send part of their drain water straight to their fuge before the socks or skimmer via a "T" and ball valve.
I ran a 200 GPH pump in my drain chamber (off to the right) over to my fuge and used a mini overflow to drain it back to the return chamber. Most of my drain water was filtered and skimmed but a small amount went through my fuge and then carried pods and such back up to the DT.
