Kub you didn't say where you are and weather the tires are tube or tubeless, these things are to be taken into account. On the tubeless tires water or calcium in MHO is bad Juju, like said is not good for the rims, though in most cases it takes years to rot them out. Pure water on the other hand will rust and freeze and that causes other problems, if you are where its warm the freezing part wont be an issue but again rust in the wheel will be. A lot of guys will use window washer fluid, or RV anti freeze, or like me 50/50 mix of the cheapest anti freeze could find, and then there is the beet juice which is heaver than water I think 30%, and I could be wrong on that weight difference, but is aint cheap. If you are running tube tires than all the above, is really of no matter because the fluid will be in the tube This is just MHO you understand.