hey Tom, see you're having the same problem I am getting feeback on cal reactors. bummer, did you buy it? I did a search on RC and looked into the vendor forums but still not gotten what I need. Never heard of the kr2 so can't say. My searching has gotten more positve for GEO brand 618,624 and negative for Koralin. if that's any help. yes I want one automated on my tank also. 90gal. good luck ,Robert