So I was putting in a new koralia and when I was done my diamond goby went missing.i thought maybe the new flow spooked him so I let it go.2 hrs when by and nothing.so I figured I feed my fish and he'd come out.nope...so I went looking and sure enough in the bottom of the overflow.tried to net him nothing.so I had no choice but to pull out the drain tube and let him fall into the sump.in there I had to fish him out by hand.then to but everthing back and clean up.what a headache.i know im not the only one whos had to deal with this.