hey guys, So I’ve got a black skirt tetra that sometimes ‘fights’ with another white skirt one in the tank. I saw what looked like crinkles or bites in the black skirts fins and assumed it was an injury, but since he never seemed to hide/show signs of stress I let him be. However now I’m seeing a few more and am worried he might have ick or some disease (he’s acting perfectly healthy however). The other fish in the tank are super vibrant, parameters are very good with nitrates hovering around 5 ppm (I have a very heavily planted 30 g). I’ve attached pictures - if he is sick should I quarantine him in a 1 gal and treat him/ would I have to treat the entire main tank? Thanks!