My sump ahs pretty much the same baffles as yours does. I'm going to be changing it around soon to alter the flow, and when I do, this is how it will work. The left compartment, where the bubble trap is, will hold the skimmer. The tank will drain into this compartment. The middle compartment will be the fuge - about 5" of sand, some live rock chunks and rubble, and some macroalgae - probably chaeto and caulerpa. Then the return pump will go after the last baffle, all the way to the right. Thats the point of using that egg crate piece on top of the baffle - to keep macro, etc from overflowing into the pump area. If you're going in the other direction, it doesn't serve much purpose.