I recentally added an oscar to my tank with my molly and pleco without realizing how aggressive they are. I moved him, but it was too late for my molly. he has a shredded left dorsal fin and 2 red marks on his face. I added salt to the water to prevent infection and the red marks look better and he is still lively and eats but there is a white film on the dorsal fin. it does not look like ich, and is only on the dorsal fin. I have maracyn but only 2 packets left and I didn't want to treat him without knowing what it is and I also have a fungus clear. my amm, nitrate, and nitrite levels are at normal amounts and there has been no erratic temp changes. 
