Plywood tank/sump designs, critique please help me

[suicyderider]

Hello here are a few designs i did last night for a future build when we move into our new house with a basement. I would really appreciate some feed back on design, will it work, is the layout good or bad, the size of the overflows and how many GPH i can actually expect to turn what return pump i will need for this setup. I am new here i have general idea but i know there is far more knowledge here so why waste it. The tank is planned to be 72''x36''x36'' with the sump being 68Lx22Wx18H with a bottomless 10Gal bio filter on each end (pic will show). I plan to use porus sponges in the first stage followed by lava rocks, then an empty space (possibly refugium?) then to the return pump in the center. please feel free to ask questions as i may have not mentioned something. Here goes nothingView attachment Plywood tank + sump flow TOP.bmpView attachment Plywood tank + sump flow BACK.bmpView attachment Plywood tank + sump SIDE.bmpView attachment Plywood tank + sump w bio.bmp