Oddball said:There is no set formula due to differences in where coral originates from and the amount of dissolved minerals existing in different tap water. Your best bet is to mix aragonite (fastest) or crushed coral (slowest) to your substrate until you hit the pH you want. Your pH will still have to be monitored, since different organisms absorb the calcium to different degrees, and replacment of the aragonite or crushed coral will need to be done..