its a neighborhood pond, they where set free in there about a year ago, the city owns the pond, you can tell that the fish had gotten to big for the previous pond, they eat everything in this pond, but they wont bight anything on a hook? and no1 feeds them
Take some corn tortillas and cut them in quarters and let them sit out till they bend. then fold them in half and again and go fishing. Ive used all that carp bait and this works the best for me anyways.
throw bread in the pond for a few days to get them eating that then fish with a bread ball and no weight so it sinks slowing like a slice of bread. koi dont eat much when the water temps drop so you may have to wait till spring. I would let them breed them you will have hundreds of them in there. there is these two ponds near my house a man owned that had koi and goldfish in. ponds are prob 1/2 acre each the land was purchased by a retailer and now they are run off pond for the shopping center and there are thousands of them in there now. toss a few slices of bread and wait a few min and throw a cast net and you will be lucky if you can pick it up.