What type pump are you using, and are you using the factory input elbow ? What is the present Flow Rate ? (Depends on the pump used, the height/distance from the sump to TOW line, the type overflow used, and diameter of input hose used.

Need more data ?

There are a few modifications that you can make to the overflows (Stockman/Durso type overflow R. Durso's 180g - Ken Stockman Standpipe ) , and you can place 3 large bricks of open cell foam in the wet section, along with a prefiltered power head to polish the water in the pump section. They are actually a pretty good design for an OTC unit, but need a bit of tweaking in fluid dynamics, and media. You should be able to move 700-800 gph through there easily ? I'd have to recheck the diameter of the sump input to verify just how high a flow rate you can acheive ?

P.S. the Sea Swirl wave generators Sea Swirl are the livin end for Planted tanks and Co2 input !!! Stick with the larger 3/4" and 1" units though with a 180 gal. tank ! and lose those AGA input pipes under a bus or something... HTH. Prof M