Originally Posted by Toby
I have never put antifreeze in my water tanks. Just get them drained. There's plenty of free space in there. The important thing is to get the water out. If all the water is out you won't need antifreeze but I always put it in my water lines and pea traps. Don't forget to bypass the wh too and close the low points before sucking in antifreeze.
I don't put it in any of the tanks, either. I'm sure some of the antifreeze does end up in the grey tanks if you are pouring enough to get past the traps. Won't hurt a thing. I do leave just a little in the black tank, but I'm sure it's not necessary. I leave the fresh water tank plug out during the winter so anything drains off there. Do the same with the hot water heater after I bypass it. I don't put antifreeze in the supply lines. I just blow them out thoroughly and have never had a problem. Maybe it'll bite me in the butt someday, but so far, so good.