You need to test your water and add whatever kalk you need to keep alk and Ca steady. In the beginning that will require you to test frequently and change the amount often. As things settle down you will be adding alk and Ca at the same rate your tank is using them. Then the amounts will gradually change and you add corals, corals grow, etc. Test less often and when they start to go down increase the amount of kalk.
There is no if your tank is this big add this much. A large tank with little coral will need much less kalk than a small tank full of SPS. And, as corals grow over time, hopefully, and bigger corals need more stuff the amount you need will change over time.
Also, at some point, if you have a lot of hungry corals, you may not be able to give the tank enough stuff with kalk and you will have to move to 2 part or a calcium reactor. A bittersweet day since it shows that you can maintain and grow a tank, but it is going to cost more now.
