What is the best method for keeping the fresh water tank from freezing while dry camping. My trailer has small 12vdc heating pads attached to the gray and black water tanks to help them drain. Can these 12v pads be used for the fresh water tank or do they use too much battery power to be practical. Can the pink RV antifreeze be mixed with the fresh water to be used for everything but drinking? My tank is totally exposed under the rig and the pump supply line comes out of the bottom of the tank making a natural water trap in the hose. Any suggestions?