The sump/fuge is in 3 parts. The first part is the fuge. That spills over into the baffle area. Then the water goes to the section where the return pump and skimmer are. The water coming from the main tank is split - half to the fuge and half to the baffle area. My return water then passes through my UV
light back into my tank. The baffle area is where to bio - balls are. I can see hair algae growing there also. I do not know that much about modifying the sump if I have to, at least for the baffle area.