I'm happy to calculate it and did attempt to do so I'm just not exactly sure where to start as I don't really have any point of reference.
Note that you won't get a single, simple answer, as there is no simple relationship between water hardness and solution composition. Solutions containing 2.6 g of dissolved CaSO4
per 1 L and 1.8 g of MgCl2
per liter have the same hardness, but different boiling points because of different van 't Hoff factors.