This isn't just calcium, it's also alkalinity. The precipitation isn't just a "too much calcium so it settled" situation, it's a chemical reaction that, if I understand correctly (not a chemistry guy), is based around the calcium and alkalinity actually binding together then dropping out of the water, forever unusable. It's sort of like adding too many people to an elevator. If it's overfilled, the whole elevator will drop, not just the last people who were too heavy. "Baby with the bath water." It's also not temperature sensitive, but it is actually pH sensitive, to a point. Higher pH is more likely to experience precipitation.
Yes, making up new water will bring your calcium levels back up, correctly. It's really not difficult. The new water already has sufficient levels (like 400ppm calcium), and the old water doesn't. Get the old water out, get the new in.
A water change is not optional here. It's already been 3 days, your livestock is suffering. Please, for the sake of your animals, change the water, and let's argue later.