My betta was fine yesterday, but when I woke up this morning, pieces of his tail were all over the sand in his tank. I flushed him out of his hiding spot and was horrified to see his whole tail was missing and a white fungus on him where it was. I put some Melafix in his tank, as well as some salt and Prime. It's pretty bad and I'm worried he won't make it. I just this week put 3 panda corys in his tank. Two died. I'm not sure if they brought the fungus with them or if it's related. Is there anything more I can do to help him, or just treat him with Melafix in the hopes he gets better? Thanks.