I'm actually very surprised how many people on this thread have killed fish that where "problem fish" or just killed fish because they didn't want them anymore.
It was not what I was expecting.... Maybe its because most of the members here are Male and are naturally the less compassionate sex.
I wont lie. I've thought about clubbing a couple of my fish because they JUST wouldn't stop being bullies. Even though I got them because their species was supposed to be compatible with my other fish.
But I would never actually go through with it...
If you do. Then I wont judge you.
I just could never do it.
...
Although, I DID buy a 55 gallon from a guy once which included fish.
But the fish were all ... well... really ugly. He had silver dollars that were all stunted and undersized. He had these weird Tetra things.
I actually did lop off their heads. But I was buying the tank. I didnt want any stupid little stunted fish. He was too lazy to find them homes or give them to the LFS. So when I got there he says "oh, the fish are still in it".
I'm just thinking "great. you moron. Now i guess it's my problem"
I would have fed them to my fish, but who knows what kind of nasties they were carrying. I dont think he had EVER vacuumed the substrate.
So anyways... now that i'm done blabbing.
If you do it. I dont judge.
I have, in a certain situation.
But i couldnt do it with fish that I actually went out and bought. or adopted.
Edit:
I have also put my fish in time out....
When i had Africans, i had a Yellow lab that was harrassing EVERYONE. I took him out, threw him in a bucket for about 30 minutes.
I put him back and he NEVER bullied anyone after that. In fact he became really low-ranking in the pecking order after that. ???