Having kept Malawi Cichlids for the best part of 7 years (Aggressive little biggers!) unfortunately euthanizing them at times became quite a regular occurrence.
The best method by far for me and what I considered best for the fish was putting them to sleep in the freezer. Obviously this can be a little trickier with bigger fish but still worth persevering with. Basically just get a tub big enough for the fish to fix in comfortably (An ice cream tub works well), fill the tub with tank water, pop the fish in and put them in the freezer. As the water the fish is in cools down the fish will naturally begin to fall asleep before it's organs begin to shut down..
Basically it won't suffer as it dies as the fish will be unconscious.
Hopefully however you won't have to try it yourself!
The best method by far for me and what I considered best for the fish was putting them to sleep in the freezer. Obviously this can be a little trickier with bigger fish but still worth persevering with. Basically just get a tub big enough for the fish to fix in comfortably (An ice cream tub works well), fill the tub with tank water, pop the fish in and put them in the freezer. As the water the fish is in cools down the fish will naturally begin to fall asleep before it's organs begin to shut down..
Basically it won't suffer as it dies as the fish will be unconscious.
Hopefully however you won't have to try it yourself!
