Ground heat will not keep a livestock fountain from freezing, as many of our competitors would like people to believe. This was proven during the testing performed at Iowa State University to develop the thermal tube. We recommend Ritchie thermal tubes for all installations. Thermal tubes interrupt the frost line and create an airspace around the water line. The airspace around the water line actually gets some warmth from the water that is coming up through the water line. This airspace keeps the water line from freezing. At the frost line, the air temperature around the pipe is above freezing. As you move closer to the side of the thermal tube, the air will be gradually colder and will be freezing at the side of the thermal tube. That is why the water supply line should not touch the side of the thermal tube. With no water running through the pipe the air temperature inside the thermal tube will eventually be the same temperature as the ground outside the thermal tube. This is the same principle as a thermos of coffee. In most cases, all Ritchie fountains, except Thrifty King CT units used in a correct application, will require a heating system to prevent freezing.