Plumbing questions

[roblarss]

I am almost ready to run my new 120gal reef setup but I am having some issues with some plumbing.

I have 4 - 3/4" bulkheads I want to use as closed loop returns and a 1" supply. My issue is space under the tank. I have 2 3/4" SCWDs. I hooked up a mag12 and was very unimpressed at the flow. I know the 90 bends (pump discharge) are an issue but I cant figure a way around them. Would it be better to have the pump discharge into a 1.5" pipe and have both SCWDs come off them?
I may be able to locate the pump behind the sump. Maintenance would just be more difficult.

I am also looking at a new pump but what flow rate would be appropriate. I want as much flow as I can reasonably run out of the 3/4" bulkheads.
Any have suggestions on how to change the piping to make things flow better?

I will be using a mag 12 as my sump return.







Here you can see all the outlets