Why does the carp in the farm grow so fast, while the domestic crucian carp in koi fish grows so slowly?

There are many reasons, mainly the following:

1, the bigger the space, the faster the fry grow and the bigger the activity space, which is equal to physical exercise. The fish pond on the farm is much bigger than the fish tank at home.

The farm can feed it 4-5 times a day, but not so much at home. Too much forced feeding will affect the water quality.

3. The technical experience of the farm can make the water temperature, pH, hardness and oxygen content more suitable.

Raising koi fish does not recommend that the cylinder be less than one meter and five meters. If the tank is too small and the optimal growth period is missed, the old fish will develop.