damaged fin

Just picked up two Oscar’s yesterday and this one was so sad looking that I felt like he needed to be rescued. I am thinking he has fin rot and possibly some sort of fungal infection? What’s the best treatment? I dosed Melafix today but I want to make sure I go with the most effective method...

Hello all! It would appear my 2nd smallest teugelsi bichir has been nipped quite visciously by one of my other bichirs last night and I was wonder if this damage is going to be permanent or of it will heal up good with care, I have a larger teugelsi that got his pectorals removed when he was...