Just how cold are you Bolters seeing these days and future winter months arriving. Just returned back from my place in Bridgeport Calif. and I was seeing pretty close to 0. I'm not quite sure at say 0 - 10 degrees would my 235' require in gallons of antifreeze to keep her from ruining my Christmas New years holiday. I checked it with one of those there 4 different colored plastic bubble gauge and it showed about 20 degrees? I'm planning on draining the water and refilling it with fresh water and of course the antifreeze. Thank you.......