So, I'm going to be living in my motorhome (small, 20 ft. long) this winter in the Anchorage area. I'll be living completely off-grid, no plug-ins. I have a good wood stove & a propane furnace to keep me warm. Solar panels, a wood stove thermo-electric generator, and driving every day (my rig is my daily driver) to keep the batteries charged. I have a little bit of 12 volt heat tape and a 12 volt heat pad on my blackwater tank and dump valve. I'm "bringing water in" in a 4 gallon jug. I've completed winterized the greywater plumbing and water heater.
How much RV antifreeze (the pink, -50 F type) do I need to put in my 15 gallon blackwater/toilet tank to keep the tank from freezing solid?
I usually dump the tank once every 3 weeks and I would like to continue using it like a normal bathroom. I can't leave the heat tape and heat pad running long (it eats my battery up quick) and I can't plug-in anywhere for power. I planned on just turned on the heat tape and heat pad about 3 hours before going to the RV sanitation dump. My waterpump pumps 100% -50 pink antifreeze directly into my toilet when I flush it, just wondering how much this antifreeze can be diluted before things freeze up (my worst nightmare).
Please help, I'm sure some of you guys know something or have some first hand experience about keeping your septic from freezing in an OFF-GRID manner. Remember, it's my daily driver, so I can't put a thermal skirt around the bottom of the trailer. The blackwater tank is un-insulated and located outside below my rear bumper. Thanks everyone.