Koi fish belong to ornamental fish, and their size is relatively large and grows quickly, generally growing to 10 cm every year. The growth range of koi in different periods is different, and koi in seedling period grows more. People who have raised koi probably understand the growth law of koi. The fastest growth rate of female koi is after 2 years old, while the fastest growth rate of male koi is before 2 years old.

Koi grows fastest when it hatches. At this time, their metabolism is very fast and they have great demand for nutrition, so koi can be fed more during this period. Although the adult koi can't compare with the seedling period, it grows very fast compared with other fish.

The growth rate of koi in adulthood is much slower than that in seedling period, and many people hope to promote their growth. To promote their growth, we should consider their suitable growth conditions, and water temperature and food are the main factors affecting their growth. Koi fish like to live at a water temperature of 21-27 ℃, and the water temperature below or above this range will affect their growth, so if they want to grow continuously, they should control the water temperature within this range. In addition, diet will also affect their growth, and feeding high-protein foods can promote their growth.