We were doing a little research online for cories, and it says in general to use half the dose since they don't have scales and are usually more sensitive.
I am definitely going to treat them as a preventative measure, but, I am not so sure they are acting weird/sick. Their fins on top are down a little, but, only half of them are and I don't know if it is clamped. Not quite sure what that means. They're like wilted down a little I guess? But not totally.
As for the shimmying, I am not quite so sure they are doing that. They wiggle up and down and side to side along the side of the tank, but I don't think they're doing it in one place/in place. And fish wiggle when they swim right? Ehh. I didn't see the one place part of what you asked before, somehow I missed that when I answered. I think that's normal behavior for them, to shimmy around (not in place).
Obviously the tank they came from was somewhat questionable, but, I am not so sure they're sick, but, they still are going to get treated with what you suggested
Also I did read a few things where people used salt and it did not harm their fish. But I am a little skeptical of that. A little couldn't hurt probably though.
And you're welcome! I can't wait to see his pic! And nice name
So you like Vikings huh? I haven't seen many episodes, but, I like the show as does my other half.