One of my female bettas has what looks like a tiny grain of sand stuck to her caudul fin. A picture would be of no use since the thing is tiny, and I could barely see it, but I know it's there. It really looks like a speck of dust or sand. She has no other symptoms and eats like a pig. She currently has a 2.5 gallon tank heated at 80-82 for herself until she is done quarantining to be released into the sorority.
The only medication I have right now is malachite green, which I don't want to use unless she is in serious danger. (I heard its pretty strong)