I should really update my build thread, but it's embarrassing how little my tank has grown in 2 years. I think starting with dry rock and jumping right into a CaRx without much demand really set me back dramatically. And I spent an embarrassing amount of money on coral that died because of lack of stability. Oh well, live and learn.
For your tank just starting over (you're not transferring anything, right, this is a whole new setup and new corals?), I'd recommend just doing kalk in the topoff if possible, or make an in-line kalk dispenser similar to the Tunze one, and that should hold you over for the first year or two. Then buy a bomb-diggity calcium reactor or two part setup (or both, as Neptune recommends with the Trident
).