nope, assuming he is using some sort of durso overflow they work by allowing air in the pipe to maintain a specific amount of suction.. always going to have bubbles.

Like everyone else, if you can shut down the sump, dry it out, silicone acrylic baffels let it set up over night and hook it back up.

here is how I did mine if your looking for ideas
http://members.shaw.ca/s.l.s/diy/sump/index.html

Steve

I realize there will always be bubbles but having the water fall vertically then take a 90° turn to flow horizontally would slow down the flow alot. The falling water from upstairs would hit the water in the horizontal pipe and cause more mixing and crashing in the pipe then nessecary. The falling water is getting backed up and building up pressure in the pipe. Once the pressure hits a certain point it has enough force to push the water out faster. I also believe this is what is causing his overflow level to fluxuate. I had the same problem in my overflow setup. I have yet to test this theory but from everything I have read over the last 6 months or so states its best to have at least a slight downward angle on all your overflow plumbing to keep the water moving. I think it would definately help but I also do agree that baffles are a nessecity for micro bubble removal.