I see so much talk about these, yet, I have no idea what they are, and what they do..
tang_man_montreal Member Aug 21, 2002 #1 I see so much talk about these, yet, I have no idea what they are, and what they do..
wingnut Member Aug 21, 2002 #3 its like a filter but it adds calcium to your tank not really need if you dont have hard corals
