ok, so after following Hendersonracings' thread I am no longer scared to death of a Calcium Reactor, and of course want one :funny: . So I started looking around and I like the Geo's and the Koralin reactors. Do these run like skimmers, ie. Get the biggest you can afford? Does anyone know about or have experience with the Koralin reactors? Do you include the sump in the volume? I would imagine you would and that leaves me with about 550 gal to work with...so do I go up to the 800gal size or down to 400 gal size?