I have a Quietflow 600 hang on overflow box... supposedly it should take
care of 600GPh. Also I have pump that is pumping from sump to the tank, it
is Dolphin DP 560. With 2' head loss the chart says it would output 460GPH.
So far so good, but the overflow doesn't seem to take 460gph quite well, I
get my sump's return area empty very quickly, this means one thing that the
pump pumps faster than overflow can handle. Any thoughts on how to solve
this?