Sump design: What do you think?

[hocky]

Below is my sump design that I am considering. This is going into a 75 gallon tank and underneath a 225g display. The return pump is a ~1700gph iwaki. The dimensions that I am figuring would put 11.5g in the skimmer section, 16.5 gallons in the return section (assuming completely filled, it wouldn't be), and 24.5 gallons in the fuge section. Those dimensions leave about 22.5 gallons for overflow in the case of a full return section. Would you change anything?
Also, how thick should the glass be? Is 1/4" the minimum? And what width should it be cut to in order to allow proper adhesion with the silicon? 1/16" less than tank width? How much flow am I leaving on the table if I plumb the intake of the pump over the tank instead of drilling a bulkhead?
NOTE: Attachment drawing not to scale. ;-)

 

[mr_x]

it looks good to me.
my sump is set up left to right. both overflows are piped to the skimmer area first. the water then passes through the refugium, and then to the return area. this way i don't get alot of debris in the refugium.
i would not put an extra hole in the tank for the return. i would definitely bring the returns over the top. you are not using the returns for flow anyway, right? i'm assuming you'll have a closed loop and/or some powerheads?

 

[hocky]

The return will be feeding two standard return pipes and two sea swirls. I will also have a few powerheads in the tank. On my current sump, I bring the intake for the return over the tank with no problems (the only annoyance being getting it to prime when it is first fired up), but in this case the intake tube will be much longer due to the tank length (like 36" of pipe to fill before the intake).

 

[mr_x]

if you bring it over, and then down into the water, how does it lose it's prime?

 

[hocky]

Only in the case of servicing the pump.