Eutanaziju vršim (fala bogu rijetko) stavljanjem u mineralnu ili pothlađivanjem premda je najbolji i najhumaniji ovaj način:
Every fish keeper sooner or later faces the unhappy task of "putting a fish down", or euthanasia. There are many methods, but my preferred method is to overdose the fish with clove oil, a very safe and ecologically sound fish sedative used as an anaesthetic to sedate fish for procedures such at tumour removal or wound care. Clove oil (active ingredient, eugenol) can be obtained through pond suppliers or health food stores.
The clove oil must be dissolved in alcohol to allow it to dissolve into the water. I use vodka. Using too much vodka will increase the discomfort to the fish, so measure carefully. If you feel you must increase the dosage, increase the clove oil only. Leave the fish in the solution for at least a couple of hours. Clove oil is a very safe sedative and fish have been known to revive after an hour in the solution.
Have a gallon of tank water in a bucket and put the fish in it. In another container, mix 2-3 ml clove oil with 8 mls vodka. Pour the clove oil mixture in and mix a little. The fish will be unconscious within minutes. I've never had any struggle or distress.