I have 4 neon tetra living with my betta in a 20 tank. I’m going to get more, and no, my betta doesn’t bother them. Everyones completely healthy, except one neon. He acts just like the rest, eating and schooling. But he had this weird fungus cottony growth on him. He’s had it for a few weeks now, and he’s still acting normal. I’ll post pictures. Should I be worried? It’s not spreading on him or to the others.