You are always telling us not to feed our fish. But the fish store tells me I must feed them, Who is right?
If you have a balanced pond, with underwater vegetation, your fish will be happy without unnecessary and artificial food introduced into the pond. If you feed them, they will grow bigger than the pond can handle, they will eat all the vegetation, so you will feed them more and more...and soon the bioload will be too big for the pond and all the fish will die.
If you have sufficient filtration, you can feed fish, but not without it. And overfeeding leads to foul and green water.