• 1
    Include natural pond plants and scraps.Variety is important in a well-rounded diet. While the supplemental diet provides many of the same nutrients found in the base diet, it also provides a variety of other nutrients essential to your koi’s health. To increase variety, feed your koi natural pond plants and food scraps.
    • Natural pond plants include ordinary pond algae, as well as other plants like duckweed.
    • Vegetable scraps like peas, carrots, spinach, leaf lettuce, and so on, are also a good choice for supplementation.
  • 2
    Provide shrimp on occasion.Frozen shrimp can be used as a protein supplement. However, they should be used sparingly.
    • Some people also provide scraps from fish they have prepared for their own meals as an occasional dietary supplement.
  • 3
    Add color-enhancing foods.Of course, koi are best-known for their beautiful colors. You can help preserve and enhance their color by feeding them color-enhancing foods every four weeks.
    • Look for foods that contain spirulina, shrimp, or krill.
    • In the wild, koi eat crayfish, which are high in carotenoids, an important nutrient for enhancing the color red.
  • 4
    Feed koi live foods.Koi may enjoy eating live foods from time to time, like they do in the wild, as a special treat. This can also be a good way to supplement their base diet.
    • Feed koi crustaceans, insect larvae, worms, and aquatic plants.
    • Also include live plants to give koi some roughage and added vitamins and minerals.

Source:wikihow