I had some problems with bubbles with my sump too, a 100 micron filter sock really helped out a lot. Check out the picture, you can see it in the sump.
http://www.maast.org/index.php?name=...pic&t=9561
It cleaned out the water really quickly after I put in all my live rock too. From what other people have said, it works well, just clean it out often!