I been reading alot of stuff online and checking out the stores. I was just wondering about Calcium Reactors. They are quite expensive so I was wondering if they are a requirement for keeping corals and such? I plan to have fish and corals but if this is something im going to need I may have to do just fish. I dont have super lighting so I only plan to do some softies and some zoo's and maybe a couple of the hard corals that dont need MH lights. Right now I have 330w of light on a 120 gal tank.