Prestone rv pink antifreeze

Grit dog wrote:
FWIW (doesn't get real cold here) I've been using windshield washer fluid since we moved to WA where there are milder winters, for my camper tanks and boat ballast tanks without issue. And its only like $1.99/gal on sale.

Water lines, hw tank, boat engine all get blown out or drained and dry stored.

Windshield washer fluid isn't a particularly good option, really, and in any event RV antifreeze is about the same price (at least around here). Most winter windshield washer fluid uses methyl alcohol (methanol or wood alcohol) as the antifreezing agent. That is pretty poisonous stuff; a good swig or two could cause blindness. You very definitely do not want to use it on any system that carries fresh water. It's also more chemically reactive than ethyl alcohol (ethanol or grain alcohol) or the other antifreeze agents that get used, though it should generally not be harmful to the typical RV black or gray water system.

It's not a terrible idea to wash your hands after handling the windshield washer fluid, even when just filling up the reservoir in one's vehicle.