I have 3 red belly piranhas, they are babies about 2in long. I woke up this morning to find that one of the piranhas had something on his eye..it wasnt a cloudy eye it looks like puss or something bugging out of his eye. If i look at it at a certain angle i can see his eye under it.. if that makes sense. They are all starting to lose their scaled, their fins are turning black and theres discoloration on their heads. PLEASE HELP ME. I called the rhode island aquarium and spoke to someone and they told me to do a water test at my local fish store. I went and they said i had high level of nitrate and to do a water change (which i did) and to add 2 t-spoons of neutral regulator into the water (before i put it in the tank) and tetra safestart which reduces dangerous ammonia and nitrate. I did all of this. Should i be ok? I am very worried and would like to help my fish. PLEASE RESPOND.