Does anybody know what is wrong with this Cory’s nose? The big whitish spot showed up basically overnight around 2-2.5 weeks ago. I’ve done two treatments of erythromycin and one treatment of general cure with no change. She’s acting normal and eating. I’m assuming it got scratched on the gravel and is now infected or something? I am planning on switching to sand soon. Not sure what to do or how long I should expect it to take to heal. Everyone else in the tank is doing fine! Thanks for any suggestions!