Hey guys, I honestly think my fish have fin rot, I did some research and their fins look like some example pictures I viewed. The fish that has it the worst is hanging around the filter more than normal as well. I just did a water change a few days ago, so my water should be clean. I have 5 serpae tetras and one emerald cory(I haven't spotted signs of fish rot on him). I read that adding aquarium salt can help heal their open wounds? Is fin rot fatal? Any other recommendations to help them get better?