Little koi can grow up. Baby koi fish of different ages can grow to different lengths. The length of 1-year-old koi fish is 10-20 cm, the length of 2-year-old koi fish is 24-30 cm, the length of 3-year-old koi fish is 37-40 cm, the length of 5-year-old koi fish is 45-50 cm, and the length of 10-year-old koi fish is 55-70 cm. Koi fish that are over 10 years old can grow to 1-1.5 meters.

Notes on raising small koi:

1. The owner should provide enough living space for the small koi so that they can live in a large fish tank without survival. They can grow freely despite the pressure of space.

2. The fish tank should not be polluted by external pollutants. For example, light will cause maladaptation of small koi, and in severe cases, it will lead to death from hypoxia. At the same time, we should also ensure that the water quality is up to standard and not change too much water at one time.

3. Provide food to small carp in a timely and appropriate manner. It is worth noting that you should not feed too much at one time, but feed small amounts multiple times.