White on neon tetras fins?

I bought 4 from my LFS yesterday. They looked extremely healthy. They all have been there for weeks. When I looked at them, one or 2 of them looked normal, and the other 2 has white on their fins. I don't know if it is ich or not. There are no specks of white everywhere, just a bunch of white on their fins. There aren't any specks on their bodies or face. There is something that looks like a little white dot on the fin, but there's like a small streak of white on the fin. They are all acting normally and eating well. Is this normal?