Can we travel with fresh tank full? We lose half on the way.

I prefer to dry camp so I fill the water tank full before I leave and I travel around mountains on every trip. To say that, I have never heard of a trailer losing its water while driving, have you checked for a crack in the tank? To test it, I would fill the tank and add some dye to it and start driving around and see if you see any leaks. The shouldn't hurt your tank but if are worried about it, just sanitize it. Would like to hear what you find.