flow rate in a refugium and sump

i am going to use 1 pump with a T and it will have about 4x the turnover rate of the tank after the headloss...i'll be using a 900gph eheim pump. Joe from AE said this would work well and i trust his opinion.

 

This is what I plan on doing since I have a similar tank design. I plan on having the 2 overflows connect and they will drain straight into my sump, from there the flow to my refugium will be coming from the the return pump with a "T" and a valve to reduce the flow going in, kind of like this set up

http://www.melevsreef.com/return.jpg

Nope, 1 pump works, as far as a "T" might have to for returns, I try to stay away from tee's and 90's, This build I plan on using sweeping 90's, true Y fittings, and 45's.

 

This is the setup I currently use and personally, I would not go this route again.   I think the T results in a lot of pressure loss.
I plan to re-do my setup using 2 smaller pumps and as few bends/turns as possible.

 

The T does result in a lot of pressure loss, but if it's throttled back properly, it can still work. It does take some tuning for sure. I had my carbon and GFO reactors running off of my return pump and when I added my frag tank, it cut flow to the display too much. I ended up adding a separate pump for that and when I reconfigure things this coming weekend, I'm going to use a bigger pump to put everything on the same return line again. There's a million different ways that you can set things up successfully and there's pros and cons on both sides.

--AJ