How Often to Change Water for a Pond Goldfish?

Pond goldfish generally need water changes every 2 to 3 days, replacing about a quarter of the tank each time. They are easy to keep and tolerate 0 to 38 C, but need decent water quality, since poor water harms growth and health. For their health, change water every 2 to 3 days and keep it clean. Although they tolerate a wide temperature range, they are sensitive to changes, so control the difference between new and old water to avoid shocks that affect health and lifespan.