Psyire
Back to you overflow drains for a moment (cause since seeing the pic I can't get it out of my head). I mispoke earlier, I looked at my Mega flow overflow again and there is a rear wall so the mid and lower inlets don't drain directly into the overflow. (duh! that would drain the entire tank now wouldn't it!) So anyway I was looking at you design and thinking of how or if it would be somthing to test on my tank.
One question I have is, did you consider that the durso is pulling the surface water off the overflow, and would it be possible to direct that to the skimmer? Do you think it would be more efficient (cause it's all surface skimmed water) or would it not make the desired flow to the skimmer. I am just thinking that even in the overflow, protiens and neutrients rise to the top where the Durso is working.
The "open" drain could then feed the fuge, maybe with a filter bag at the discharge?
... just a thought