Yup, exactly, the reactor makes it the easiest method for controlling Alk and CA, but it is usually the most expensive way to do it also. You have half the battle won, you have the reactor, now you just have to set it up and learn how to dial it in and adjust it. This can wait several months after you first setup the tank though, it takes a while before they are needed unless you fill the tank with colonies of SPS corals right off the bat.