hole

It definitely isn't ich....only other thing I can think of is hole in the head. I recently lost a lot of lemon tetras from something that would eat away part of their face gills and body, like lesions. Could it have been hole in the head all along? here are some videos of the tetras and...

How do I treat him? I went to PetLand and they seemed to have nothing to treat it. This guy is big (6 inches). I have him in a separate tank for now with the temp cranked up. Any meds I should give him and where do I get them from? Thanks for any advise and help.