controlling air "bubbles" from Durso standpipes

[hqgc]

I have two 1.5 " supplys to my sump that are dursoed from my tank. The amount of air that enters my sump from my standpipes is quite large.
My question is
1. Is there anyway to control the air intake into the standpipes without causing problems inside the overflow.
Right now the the water level is just above the halfway mark of the street ell 90 elbow in the overflow.