Here are some factors that can affect their lifespan:
* Water quality: Clean, well-filtered water is essential for their health.
* Diet: A balanced diet of high-quality goldfish flakes or pellets, along with occasional treats like blanched vegetables, will keep them healthy.
* Tank size: They need a spacious tank to thrive. A good rule of thumb is 10 gallons of water per goldfish.
* Temperature: Goldfish are coldwater fish and prefer temperatures between 60-72°F (15-22°C).
* Stress: Overcrowding, poor water quality, or improper handling can stress goldfish and shorten their lifespan.
It's important to note that fantails are susceptible to certain diseases, so regular monitoring and prompt veterinary care are crucial.