Hi, I live in Knoxville, TN and typically we don't have harsh winters but currently we are facing overnight lows in the single digits. We have a flowing pond in our backyard that feeds into a pond that holds 5 koi fish. My wife and I are freaking out because we are new pond owners and don't know what to do. The pond is frozen over and the pump is making a loud humming noise. We inserted a de-icer this morning, thinking that will help things. We are debating on removing the pump but I'm concerned about the well being of our fish and our pipes bursting. However, the sounds would indicate my pump is about blow and facing a host issues. Any help would greatly appreciated. Thank you!