i've learned that pushing more volume through a sump is bad news. The trick is to run your large pump as a closed loop and a smaller pump on your overflow.
I have aprox 3000gph running thru my sump right now and it sucks because there are microbubbles, so as soon as I get a smaller pump (500-700gph) I'm going to put the large pump on a closed loop. It should hopefully cut down on noise too.
3000gph might not be a problem for someone with a 200gal sump, but for a 35gal sump, it's way too much.