I noticed a few days ago that all four of my card. tetras seem almost like part of their back fin is missing, like something has torn part of it off. Well tonight i'm noticing a couple of them are acting kinda strange, their twitching against the front of the tanks glass, I guess i don't how else to explain it
Anyways, I noticed one has some white on its tail fin.
My tanks a 28 gallon, been set up for 4 or 5 months now. All my water perameters are in check. I do a 15% water change every week. I have the 4 cards, 5 serpae tetras, 2 mollies and 3 cories. All the other fish seem to be happy and healthy.
If I can give any more info to help determine what or if theres a problem here, let me know.