I like the sump/fuge set up...:yes:
Am I seeing this right...pic 3 lower left is the fuge...??
Looks like a good bit of water coming in there already...lotta "surface" movement...can you divert/direct the flow to get some of that "oxygenated water to the bottom of your fuge...
Maybe an additional pipe and 45 elbow to get it to flow "down" and "circulate" rather than "across" the top and over the edge to the sump...??
29x20 is good footprint...and 11" isn't too deep so you should be able to get the bottom water moving and rolling to the surface with the flow I "see" in the pic...
You could "measure" flow by sticking a hose in the outlet and filling a 5 gallon (or 5 in a 7 gallon) bucket and "timing" it...Then do the math to figure sec/gallon, gpm, and GPH...
I'd say if your getting 250-300gph through that fuge you'd be doing good...