I live in Minnesota. About the only thing you can add is calcium cloride or the beet-based product, Rim Gaurd. Anything else is too expensive, toxic, or will freeze & ruin the tires/ rims.
I don't like antifreeze because it is too light; it is toxic; and it is far too expensive for the concentration I need; my tire dealer would kill me if I had him service my tires & I contaminated his good CC supply with antifreeze.
Straight water would only work if you are in the far, far south.
Best is CC mixed with water inside a tube, 75% filled in the tire. You _must_ have an air space in the tire of 20 - 25%. Generally put the valve stem to the top - 12:00 oclock position, and fill with liquid to there. The top of the tire should be air. This will give you the 75% fill.
Fill the tires that need weight or traction, don't fill the ones that already have enough of both - for example, don't fill the fronts if you have a loader, but then if you don't have a loader & use lots of heavy 3pt equipment you might want to fill the fronts only, not the rears.
CC is a form of salt, and it does cause rust if exposed to oxygen. The trick is to have good tires & tubes, maintain them, and flush off an pills right away. The horro stories of rims rusting out come from tractors that have sat, with no maintenence, in a grove for 30 years...... Somethig you take care of, the CC is a lot better & safer for all than toxic antifreeze. Sealed inside the tire without much O2, there will be no internal rust.
--->Paul