Calcium & Alk. Additives - What's best?

[OCDP]

Just wondering what's the "best" or most commonly used Calcium and Alk. additive? When I had my first reef, I was using Seachem products (the powders you mixed with top-off water) Can't really recall if it was all that great or not... and wondering if there's a best additive?? I know there's liquid buffers and powders, don't know if that makes one better than the other.. open to any suggestions.

I am only keeping softies for now, but I will be adding SPS as soon as I can, and want my calcium and alk. levels proper before doing so. I haven't been monitoring or adding any buffers yet seeing as it's just real basic softies in my tank right now.