[JRTJH]

RVDad,

Just a note of caution: If you poured your antifreeze into the fresh water tank and (at the same time) are suggesting that there was "up to 3/4 of a tank" of water, chances are very good that your antifreeze was diluted to an extent that it won't protect your RV plumbing from freezing. As an example, if you had only 3 or 4 gallons of water remaining in the tank and poured in 3 gallons of antifreeze, you've diluted your antifreeze to at least a 50/50 mix. That means the "advertised freeze point of -30F may actually be +15F"

That said, RV antifreeze will freeze. The "protection it provides" is that it doesn't expand as it freezes, so even though it's slushy or even solidly frozen, there's no "damage incurred from expansion"... On the other hand, if your antifreeze is 1/2 water, the water in the mix will expand and can cause damage to your plumbing.....

So, if by chance, you poured your antifreeze into the fresh water tank and there was "more than a token amount" of water remaining, you may have a "false sense of protection" and your RV may be subject to damage....

Since I wasn't there and don't know what you did, I'm just bringing this to light as a precaution. If none of the above apply, then please disregard.....