i have now had my tank cycling for the past 3 months, it is a 210gal (72 x 24x 29T) mixed reef with lots of SPS frags, some LPS, zoas, palys, and a few softies , but i know that i will eventually be needing a Calcium Reactor but have ABSOLUTELY no clue as to what i need, to look for when buying one (i.e...ph probe, media, pumps, cylinder type, size...etc.) and want to see what you guys recommend.....thanks for ur time and suggestions.