RV Anti-Freeze in black and gray tanks.

[fastcat]

Great tip on the water softener. I use it in my tanks anyway, along with a little cheap laundry detergent, to help keep them clean.

[SteveLevin]

We actually used windshield wiper fluid to pour into the tanks because it was 89 cents a gallon. Obviously, this is just for going right in the tanks as it's potentially toxic. The level of aanti-freeze protection is a bit less, but to be honest, we used it in sub-zero temps and it kept everything from freezing by the valve (which in our rig is not a heated area).

Steve

[Gordon Dewald]

You should have heated tanks?? If so and you are staying in it it should be good for the temps you are discussing.

[SteveLevin]

oh! One other thing to think of. If you have an icemaker... you probably want to find the cutoff valve for it, and drain water from it if possible. That water line almost certainly routes along the back of your fridge, which means it is directly exposed to the elements behind the fridge cover on the outside. It's a small diameter line, AND usually copper...so it is nice and conductive to freezing and bursting.

Steve

[sevenmacs]

20's and being stationary your tanks should be ok, our Fleetwood tanks & water bay are heated by rear furnace. Although I did put some flexible dryer tubing on vent to divert hot air further into compartment (mine comes out in side compartment ) Fridge water supply needs insulated or drained, also keep hot water heater on. During one very cold stay I did put a small heater in water bay. Some use a 75 or 100 watt light bulb in a trouble light as well. I also use when traveling in cold weather ( Colorado to Florida in January ) 1/4 foil backed insulation to help insulate water bay, as well as a small 12volt heater.