Hi all! I just finiahed moving all my fish from the old tank to the new and I noticed a white spot on the dorsal fin of one of my Venezuelan corydoras. They were quarantining for 2 weeks before I moved them and its acting fine but i didn't see this before today. Any idea? Should I move that one back out to quarantine or treat the whole tank if its something like ich? Im new to the hobby so I've never encountered anything like this before.