Okay. Take my title any way you like. I think this idea may just work. It's already been tested down to 19F.The 9"x9"heating pad ($9 at Walmart) is a stay-on one setting control and the perfect size for a Bright Tap. This setup should be a whole lot cheaper to operate than an in-tank heater. The pad is secured with a shoe lace to the double walled Igloo tank so it folds over the Bright Tap. Chickens help me re-tape the water heater blanket. Such efficient helpers. An old wool blanket sewn into a bag is pulled down over the water heater blanket and tucked under at the bottom to keep busy beaks from tearing up the insulation and eating it, and it adds additional insulation. I believe there's enough insulation to keep the tank from freezing and the heating pad will keep the nipples from freezing over. I've yet to test it in temps below zero F, but I'm pretty confident it's going to work.