No reason to dose that tank. Before you add corals, just test the water for Ca, alk and Mg. They should be fine and if they are in range, just keep doing weekly water changes. The salt mix will replenish elements. If the initial tests show those parameters are low, do a series of 30-50% water changes over a few/couple days and test again. If that doesn't balance out the parameters then you can dose to bring things in line. You have nothing consuming those elements currently and unless you run a full blown SPS tank, I doubt you will ever need to dose.