As I was checking on all my fish, I noticed that Links' fins looked odd. The tail fin has a small tear, his dorsal fin has a little bit of black and ragged edges, and his anal fin has a strange lavender/gray-ish coloring on the edges. I think it MIGHT be fin rot, and unfortunately I can't say if this has happened overnight, since I was doing errands all day yesterday. I don't have a picture, because he darts away whenever I hold my phone up to the tank. But all of my parameters are good, just had a water change yesterday, he ate fine, and is acting normal except for his appearance. I'm also worried it might be the unknown disease that mostly affects blue fish (he is a blue-ish fish) but I don't know! Please help!