You can eat cabbage leaves. It is best to feed synthetic granules, bait, bean cakes, vegetable cakes, bread crumbs, fish worms, clams, crab meat, radishes, duckweed and so on.
Extended data:
Koi fish is all red, which means he has no land. It is also called flying carp and red carp. According to japanese koi's evaluation criteria, red soil and worthless fish species were eliminated, but Fei carp originated in China and was the ancestor of modern japanese koi evolution.
People in China like red, and parks and release ponds like red carp, which means celebrating and prolonging life. There are varieties such as German Red Landless and Silver Scale Red Landless. What is rare is that silver scales are red and landless. Red land can be divided into red eyes and black eyes. Red eyes are the most precious and very rare.
References:
Baidu encyclopedia-carp