I am happily using the ESV B-Ionic two-part Calcium Buffer System. Early on I added Kent Marine Liquid Calcium to get my calcium up, but have not had to use it for a long time.
Every other week or so I add some Kent Marine Iodine - just for good luck
While we have only soft corals I have thought of installing a calcium reactor just to take the daily task out of the mix. We are taking a one month vacation in April and I need to ramp up to a more 'low maintenance' set-up that a tank sitter can handle easily.
Seein my pH low some time ago I picked up Seachem's pH 8.3 Marine Buffer. It was supposed to raise my pH to 8.3 without over-dosing. I got no results and hated the process anyway. So I stopped. My pH has been 8.1 practically every test since the beginning. The sea water I buy from the LFS is 8.1. Sigh. I'm not going to fight it... (Unless of course you all convince me otherwise.)