Hi all. I'm new here and was hoping I could get some help. I have two Goldfish. One of them is definitely sick, but I have no idea of what is wrong. There are no spots and nothing that shows what is wrong, but I have noticed that she isn't swimming around like she had before. There is definitely something wrong.
I've never given fish medicine, and I was wondering if I could put fish mox in the tank with the hopes it will help her and not affect the other fish. I have them in a 20 gallon tank. The other fish appears to be fine, and hopefully will remain fine. I'd sure like to try to save her! Any suggestions are appreciated!!