How long can goldfish live for when from a carnival?

Answer 1

Managing a petshop I can tell you that carnival goldfish are feeder comets. They cost normally a few cents and are mass produced to keep costs down. Health is not a normal concern when dealing with these fish that are breed to feed other fish nor are breeding qualities. I have seen people get these and place in their pond or tank and years later they are still doing very well. Goldfish produce a lot of ammonia so proper filtration and oxygenation are required for these guys. Around 12 year lifespan for these guys though some have been reported to live past 18 years.