What is the ideal temperature of water for goldfish?

Goldfish are coldwater fish, and as such, they prefer water temperatures between 65-72 degrees Fahrenheit (18-22 degrees Celsius). Water temperatures outside this range can stress the fish and make them more susceptible to disease.

In general, it is best to keep goldfish at a consistent water temperature, as sudden changes in temperature can also be stressful for them. If you need to change the water temperature, do so gradually, over the course of several days.

It is also important to remember that goldfish are not tropical fish, and cannot tolerate high temperatures. If the water temperature gets too high, the goldfish may become lethargic, lose their appetite, and eventually die.