Plumbing Problems

[sleeman]

I have a 75 gal with 33 gal sump/refuge. About 25 gals for the sump. 1.5" durso standpipe into 1.5" plumbing into sump. There is a T to a 3/4" dropping into the refuge. The 1.5" then continues and drops into the sump area. I am running a mag 18 into a 1" pipe to a 1" manifold with three soon to be four returns at 1/2". I have got the durso under control, however I have a ton of air going into the sump. I am getting a lot of microbubles in the return to the main tank. I know that I could turn down the flow or put a couple of dividers in the sump, but would like to save these as a last resort. Is there anything else I can do to help eliminate the bubbles. Would up sizing to 2" above the bulhead help eliminate air or would it draw more in? Any other styly of standpipe I could try. Link to pic of sump. Couln't figure out how to paste the pic in.
http://www.canreef.com/photopost/sho....php?photo=273
Any ideas would be greatly appreciated,

Cheers,

Al