FWIW I run approx 500 gph through a 20 gal sump/fuge w/ a similar design. The baffles I used are a little over 12" high, so the water basically flows over my fuge compartment. This means even though I have 25x per hour turnover going through the sump, the flow that gets down into the fuge is indirect and pretty calm. I even had a ph in there at one point to increase the flow some, but since removed it. It basically depends on your set up. A low baffle before the fuge usually means more direct flow through the fuge compartment.All of the water received by this sump will flow through the fuge compartment