Click the thumbnails for bigger pix! Installing external Durso's: FPT tees attached to bulkheads with close nipples: View of the horizontal overflow from left side: Ready to cut and dry fit. W/D is temporary until I build a sump, just using it to test the plumbing and overflow: Drain plumbing installed. Still "rough" where it empties into the sump. I'll be running a 6" wide or so shelf along the back, notched to accept and steady the plumbing. I angled the plumbing to place a pump in the future for a closed loop (hopefully the shelf will be wide enough). All elbows are 45's, no 90's: I don't have a decent pump yet, so will be testing with a *gasp* Rio 2500. Thinking about a Mag 9.5 for this particular system - at 5' it should push about 750 gph. The real "flow" will come from a closed loop or powerheads. BTW, I got tired of ftp'ing and linking pictures to my web sites so I signed up with Photobucket - it rocks! Get it if you don't have it - all the code for the thumbnails/links was auto-generated, just copied and pasted (and added my comments).