ohh Nooo. too big of a pump???

[Steve-O-]

when you do you plumbing for your sump put a valve on the line to the tank. Doing this will help you control how much flow you can have i know in my old 75g i did this i have a 1200 mag as well. its better to have more then less i think because you never k now when you need more flow or less flow. I did a split as well i had a small flow going into my fuge with a trickle into my tank and rest of flow into my tank.

I also had 2in drain and 1 1/4 return worked good