• Choose a quality pellet. When deciding what to feed your koi, think of it in two parts—base diet and supplementary diet. The base diet should provide all the essential proteins, fats, and most of the vitamins and minerals your koi need to survive. Commercial pellet food is the most reliable, convenient, and healthy option for a base diet.
    • The protein content in food pellets should be at least 30 percent. Protein content in pellets varies greatly depending on manufacturer—usually between 25 and 36 percent—so read labels before deciding.
    • The primary source of protein should be fish meal or soybean meal.
    • The fat content (from fish oil) in the pellets should be at least 5 percent.
  • Feed koi small pellets. Food pellets come in a variety of sizes and you might think the bigger the pellet, the more nutrients it contains. This, however, is not the case. Small pellets provide the same nutritional content as large ones and are easier for koi to ingest and digest, reducing the danger of intestinal impaction.
  • Soak pellets in pond water. Before feeding your koi, soak their food pellets in pond water for at least 30 seconds to one minute. This will make them safer and easier to digest.
    • This step is especially important when the feeding frequency is low or fish are especially hungry, otherwise, they may consume the pellets too quickly and end up eating dry pellets. Dry food can expand in the digestive track, increasing the risk for life-threatening internal blockages.