its not really that mean to kill the fish... if you kill it in a humane way then the fish doesnt feel any pain and its much bettter than neglect or giving it to an owner that might not take the best care of it... your saving it from the suffering it might incur if u give it away
My loach is healthy, about 2 inches long. It killed the one fish I was really worried about and seems to be hiding more since I got 2 dojo's. I put a big pile of sea shells in a corner of the tank and it loves to explore in there. For freezing fish, I had a vet who was treating my koi for aremones and it was a long, slow death. After all the antibiotic injections I had given them and salt baths and I knew it was time for them I would put them in a plastic bag of pond water and put it in the freezer. The vet told me that it's like hypothermia in humans, they get really cold, go into a dorment state and just never come back. I always added extra salt to the water as a natural anesthetic and they went quickly and peaceful. There was no struggling to breathe, just calm. This is only for pond koi, I have no idea if it's the same for tropical fish since their surrounding temp is much higher than koi. Anyone know a vet who has an opinion about this?
My fish vet recommended the Vodka bath also. He said it was similar to the euthanasia practiced on larger pets. They just sort of "sleep away". It still makes me :'( . So other than that little bit of information, I will leave this post to the rest of you.