Thanks for the info. There was a small leak in the deepest part of the pond (9 feet) and the other three holes were under the dock. My pond was dredged two years ago to steepen the banks and to remove the cattails. However, the cattails are slowly growing back and bringing the muskrats with them.

Has anyone used the self-weighted PVC aeration tubing? I ordered some today and will give it a try. I have two diffusers. One with a 50 foot run and the other with a 100 foot run.

I didnt realize muskrats were so destructive. When we first installed our aerator 9 years ago, a muskrat had chewed into our electrical line. I am tempted to get some dynamite if they cause anymore damage.