tank is a 90g and I'm planning of keeping mainly sps and clams with about 4 smalls fishes. I want a return pump than can give me great flow and that can be split in 2 return without loosing to much flow. Later when I'll be ready to introduce sps in my tank I'll add a closed loop with a seaswirl.

I use my mag 12 split into two 1" returns as I wanted a lower flow so I wasn't blasting any paticulat coral with it.. 12 gph though a 1" line is a hard flow. if you split it like I did and still didn't feel it was hard enuf you could always put reducer bushings in the line the restrict it to two 3/4" or even two 1/2" lines (thay way you can change them and even mix and match as you see fit.) personaly I just used the return to make a medium constant curent through my rocks and I use my wave maker to make the water movement in the rest of the tank. if you don't want to use power heads then you will have to use more than just a mag 12, maby 2 of them.. the first split into 2 1" lines to make a genera flow and the second put into 4 to 6 1/2" lines to make you oposing flows.

Steve

I'm runnining a Mag 12. My "Durso" is 1 1/4", 1" bulkhead and return line.
It CANNOT handle the flow. My return flow valve is opened just over half way. I've also divided the return outlets in two to "disperse" the current.I'm unsure on the actual GPH I'm getting but it's sufficient when combined with the 801 powerhead in the confines of the 60g corner tank. Any more circultion and it would be a raging river and I'd only be able to keep Salmon.Is your pump installed in-line or submerged ? I find my Mag 12 a little noisy in-line.
I'm rather new to this board but I hope regional, religous, and political/geographical differences are not a contentious issue amongst us all. I get enough of that crap watching the news...

I have never seen any of that stuff on this board. The only regional differences might be that some Far Westeners don't think Calgary water is as great as I think it is, but then even some Calgarians disagree on that topic. We have never had any real wars though. I myself am glad for that. My philosophy is simple ;"If it works for you, great" :D :D