Can't put my finger on the problem. Came home yesterday afternoon to find one of my angels hanging on to life by a thread. His fins were fine, scales and color good, no holes or other problems that I could see. The other day I had made a comment to myself that both the angels seemed to have a lot of body slime. It was clear and looked just like their slime coat the only reason I saw it was the over flow filter left some bubbles on it when they swam through the current. Don't know if that has anything to do with it the other angel, catfish, cardinals, and betta seem to be fine. Anybody got any suggestions. I checked the parameters last week and this tank (75 gallons) had the best readings of all . Help help Help. But it isn't an emergency since he died already.