I've already started looking for a new tank for the firemouth! He was an impulse buy "doh" just had to great of color to pass up. It's still really strange though, as the parrot owned the tank for a while, even with the firemouth. Plus the parrot will push around the sev that's now a little bigger than him, and the sev pushes around the firemouth.
I didn't mind the clashes before as they where just minor, no biting just a short chase and that was that, but the firemouth has a spot on him now that looks like a bite mark, and the parrot is in hiding most of the time. I believe that it is his personality to hide a lot as he did that before the firemouth, but he was coming out more and more before. Plus his hiding spot changed so I have to look for him in order to find him.
They are about the same size now.
I've got a spare 20G in the house is that too small for the firemouth.