Your koi began as dinner in a rice farmer's pond

The fish gliding under the lilies started out as a winter food store.

In the snow country of Niigata, in the mountains of northern Japan, farmers kept common carp in the ponds that fed their terraced rice fields. Carp are hardy, they tolerate cold and murky water, and in a region buried in snow for months they were protein you could rely on.

Somewhere along the way, farmers noticed the odd fish coming up red, or white, or patched. Instead of eating those, they kept them back and bred them to each other. Generation after generation, a food fish turned into a living pattern — what the Japanese call nishikigoi, brocaded carp. They were shown to a wider public at an exhibition in Tokyo in the early twentieth century, and the hobby spread from there.

Why it still matters: koi are carp, and they never forgot it. They are powerful, long-lived, and they get big — far bigger than most new pond owners expect. They root around the bottom, stir up silt and will flatten delicate planting.

So a koi pond is not a scaled-up aquarium. It needs real volume, real depth for winter, and filtration built for heavy waste. Plan for the mountain fish, not the ornament.

If a koi goes off its food, hangs listlessly or develops ulcers or raised scales, speak to a vet who works with fish — they do exist, and pond keepers are their bread and butter. 🪷