A couple weeks ago moved a Guppy to my Dads tank. He has seemed to been doing well. Today when I stopped by to feed, he was floating at the top and spine seemed kind of bent. He would occasionally swim after food but not much. I’ve never set up a QT tank, but have seen you could use sterolite or Rubbermaid bins. It wouldn’t be cycled and I do have a never used internal filter for a 10G. What to do?