Vet inte om det hjälper men jag skriver av den delen ur Coral propagation av Anthony Calfo som berör detta: Fish die but invertebrates survive: possible fish disease if the event occured over an extended period of days,toxin exuded from the flesh of a fish (boxfish,soapfish,mandarins,perhaps) or an invertebrate(sea cucumber),possible oxygen deficit(test for it),contamination(life fresh anti-perspirant from your freshly dipped armpit in the tank or any fragrant household chemicals) or stray voltage.