I have a 90 gallon reef with a 30 gal sump and a 50 gal refugium. I've been using the twolittlefishies 2 part cal/alk additives but am thinking of upgrading to a calcium reactor. to be honest, the whole thing seems a bit daunting. Are they very hard to set up? Maintain? And is there a model anyone would recommend (or, I suppose, recommend against?) Any advice would be much appreciated.