camper rich said:RV antifreeze not as poisonous and regular antifreeze. A quick search found this:
PROPYLENE GLYCOL – This type of antifreeze is only available in RV shops. It is non-toxic and the safest for all types of RV plumbing. This antifreeze is non-flammable and does not taint water systems. Propylene glycol is a lubricant and will actually work to extend the life of the seals in your toilets and faucets.
Regular antifreeze is ethylyn glycol--very poisonous to pets and people.
I doubt just adding the toilet chemical to the water will keep it from freezing. You may want to experiment with that at home.
Switched from idea of using deodorizer tabs to using windshield washer fluid...I know it does not freeze... and good idea to confirm when diluted if it will protect the porta-potty....we have some zero nights coming up...