Hi there,
I have had my tank for several weeks now, and things were mostly going well; my water was clean, my fish looked happy and healthy, and none of them were picking on anybody else. I had a several guppies and few mollies and sword tails. Several days ago, my male sword tail started getting very shy, and just "sitting around" in the back of the tank near the bottom. During feeding I tried to get a good look at him, and found he had something white sticking out from just bellow his eye. it was stiff, but appeared to flex at the point of attachment, and I feared that I had allowed some foreign material to get into my tank and stab the poor guy in the eye! He soon became listless and weak, and even got stuck to the filter (which is the appropriate size for the tank) while still alive. I used the net to get him off, and he died later that day. the next day, I noticed the same process start on my oldest, largest, and most dearly beloved guppy

she is also now dead. I am very worried, especially because one of my mollies, and another of guppies now have the same thing behind their fins, and the molly is developing what looks like an abscess because of it. I greatly fear that some sort of parasite has somehow gotten into my tank and is killing my fish! any suggestions?