OOPs, I forgot to test my water again. I just realized that other than checking salinity when I do a water change, I haven't done a water test in at least a decade. The fish ain't dieing, and the corals keep getting bigger. I better go back and read my books to see why it works that way. Maybe 240 gallon tanks, with a deep sandbed, a good skimmer, and a calcium reactor are just naturally foolproof.