So my sump is not the usual set up its a forty breeder and one baffel to make the fuge on one side of the sump my drain tees off with gate valves to control flow to the fuge and sump my skimmer is on other side of sump and return pump in middle . My ato keeps water level constnt enough for the skimmer what i like about tgis set up which i didnt make btw came like this is i can turn off refugium and tank will still run while i do fuge work as if the fuge was center you cant do this . Now ive seen thing go bad by haveing fuge in center and then people messing and stiring stuff up then haveing to turn it back on so the sump is working . So being able to turn off fuge part and still have a sump and skimmer working is a huge advantage and wont ever run a fuge any other way . That being said plenty people run fuges in middle no issues but ive seen few have issues so really up to u and skimmer placement really depends on what water level works best for it vut usually good idea to have it by the over flow lines to get the gunk out before hits fuge so less build up in fuge