Goldfish can live up to 30 years if they’re provided with proper care. Goldfish need a diet that includes dried food, such as generic brand pellets or special feeder fish like brine shrimp; you should also clean your tank regularly so it smells nice and fresh!
A lot of people neglect the fact goldfishes are social creatures who may not do well living by themselves in isolation – some varieties have been known to live up 40-50 years but this isn’t common for most types unless cared for properly from an early age.