How to Look After Koi Fry

Koi are beautifully colored fish which originate from China and have grown popular in Japan. They grow up to 3 feet long and are a popular choice for decorative man-made ponds in gardens and commercially used ponds. They generally reproduce in spring or summer in which the breeding process can last about two to three days. Koi fry are tiny and clear in appearance. They need special care early in life to ensure survival.

Things You'll Need

  • Aquarium setup
  • Water testing kit
  • Crumbled egg yolk
  • Brine shrimp larvae or fish flake food
  • Tropical fish pellets
Show More

Instructions

    • 1

      Remove the fry from your pond or large aquarium setup. Place the fry in at least a 60-gallon tank or separate pond with plenty of live plants. This is so that other large fish, including the parents, do not eat them.

    • 2

      Feed fry sparingly. They don't swim until they reach the water surface for the first time for air which will be about two to three days after hatching. Feeding needs will change often for the first two weeks. For the first feeding, crumbled egg yolk will be sufficient, followed by brine shrimp larvae or finely crumbled fish flake food for the first two months. Thereafter, feed the fry approximately one flake per two fish. It might be difficult to know how many fry you have, but estimating should be fine. Koi fry at about 1 inch eat only about a half a flake a day. Overfeeding can decrease water quality and require more frequent tank or pond cleanings. When koi reach between 1/2 inch and 1 inch they should be ready for tropical fish pellets.

    • 3

      Test the water every few days as water quality is important in the early life of fry. Water changes and frequent removal of remnants left over from feedings are vital to maintain clean and oxygenated water.

    • 4

      Transfer the fry when they grow to about 1/2 inch to 1 inch back to a pond or a larger tank, but away from adult koi. Pay attention to the fry as they may cannibalize one another. Separating fry that are growing at a faster rate and placing them in another tank or pond may minimize this.