>I suspect that the high phosphates cited were not really the cause of >death. People tend to look for causes and when they find something out >of whack, quit looking and settle on that. The vitamin C thing is worth >some looking into though. I intend to pursue it. Thanks. > I'm inclined to agree that it is not necessarily the high phosphates, but algae blooms and other little critters that may bloom as a result of phosphates or algae blooms may ultimately be the cause of some so-called unexplained deaths. Oxygen depletion if you turn out the lights on a tank that is experiencing an algae bloom could be a factor. There is probably plenty of microbial life that would feed on an algae bloom, some of which may be harmful to the fish. ______________________________________________________