+1 on Matt's answers.
I'd also add, given you say you're a newbie, are you planning on setting up your calcium reactor already? I was just going to suggest holding off on doing that until you have a handle on your tank's stability. If it's a new tank, take a few weeks to understand your tank's calcium demand. You might find that just doing manual dosing of calcium and alkalinity supplements (2-part) is good enough.
Good luck!