Preferably groundwater, outdoors, build a large shed to raise koi or goldfish, feed some artificial food, pay attention to the density, it is best to simulate the practice of mulberry fish ponds, that is, raise silkworms around the fish ponds, so that the silkworms' feces to feed the fish, or you can also raise some, such as pigs, pig manure to feed the fish, can reduce the cost of

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