Earlier today I go to feed my Oscar and his skin looks as if its just peeling off. There is all white stuff on his body, on and around his eyes, and on his fins. He is currently in a 150 gallon tank with a 2-3 inch jack dempsy. The oscar is about 5-7 inches. Just now I went to show my mother him and I noticed that the thermometer was broken in half and one half of it was in the gravel. There was a whole dug out where it was in the gravel. Is the mercury dangerous for the fish? Could he have been trying to eat it or something? What is wrong with him, and is it possible to treat? Tomorrow I plan to have pictures. Also, this tank used to have my convict in it that had pop eye about a month or 2 ago, but I removed her once I noticed it and tried to treat her in a 10 gallon and she later died.