Koi fish always bites fish with fried scales. In this case, you can change to a big fish tank.

Koi fish always bites fish with fried scales, because it has bigger bacteria. In this case, it is recommended to keep the water clean. It is suggested to change the fish tank, the space will be larger and there will be no more bacteria.

Koi fish, also known as flying carp, belongs to freshwater fishes in subtropical and temperate regions. It is an ornamental fish evolved from wild edible carp.