Seeing your carefully planned water garden bloom into
hundreds of colors and textures throughout the season is, no doubt, extremely
rewarding. Flowers and plants require cultivation to reach their potential, and
the results validate your hard work. However, don’t forget that your Koi also
need “cultivating” to maximize their vibrant colors, growth, and longevity.
Koi are omnivorous opportunistic feeders—meaning they need
both protein and plant matter in their diets and will look for these nutrients
anywhere they can get them. It’s fun to watch Koi scramble to eat bread crumbs
or Cheerios, but depriving them of a balanced diet created for their
physiological needs affects their color and energy level and decreases their
ability to fight disease. Choosing quality Koi foods and learning how much and
when to feed them are critical elements in maintaining your pond.
Koi are naturally bottom feeders because of the shape of
their mouths, but there are several reasons why it is best to use floating
foods. Bringing your fish to the surface allows you not only to enjoy their
beauty but also to check for injuries and overall health. Over time, your fish
will recognize you as their food source instead of a predator and will spend
more time in view when you are around.
Buying Koi flakes, pellets, or sticks is not as critical as
making sure the consistency of the food allows for easy digestibility. Since
Koi do not have teeth or stomachs, they are unable to break down food in the
same way we do by chewing and with acid digestion. Anything they cannot process
is excreted back into the pond, increasing your chance of algae blooms. Choose
a floating food that is not too dense but does not break apart when thrown into
the pond. Water should soften food just enough to allow the fish to break it
down with the pharyngeal bones in the back of their mouths before passing it
through their intestines.
Healthy Koi require the proper amounts of proteins (amino
acids), fats (lipids), carbohydrates, vitamins, and minerals. Proteins increase
growth and reproduction, and fats give fish energy. Look for 31 to 42 percent
crude protein and two to three percent crude fat on the nutrition analysis
panel. While carbohydrates offer an energy boost, their main purpose is to help
fish process food nutrients, and vitamins and minerals regulate their
metabolisms. Using manufactured maintenance foods offsets what fish would
normally scavenge in the wild but are unable to get in backyard ponds.
Because fish meal provides the bulk of protein in fish diets
and is easier to digest than most grain proteins, it should be listed as one of
the leading ingredients for staple foods. Ground corn is often considered
filler; however, corn gluten and flour have been tested to be highly digestible
and provide needed nutrients and vitamins. Koi also need Vitamin C to develop
their immune systems so make sure foods include ascorbic acid.
While synthetic ingredients in human food continues to be
debated, this issue is not so critical for Koi food since fish process
synthetic and natural ingredients in the same way. Natural ingredients are
preferred, of course, but food manufacturers may need to use synthetic
ingredients to ensure the fish receive balanced diets based on their natural
Seasons and water temperatures affect the type, amount, and
frequency of Koi food to use. During the warmest part of the pond season, when
water temperatures are higher than 70 degrees, fish digest their food in four
to five hours which is why feeding staple foods three to four times per day—and
only as much as they can eat in about five minutes—is recommended. To reduce
maintenance and potential problems with water quality, be sure to remove any
uneaten food with a net before it sinks to the bottom. If you want to enhance
the reds of your Koi, alternate feeding a staple diet with color-enhancing
foods that contain spirulina, shrimp, or krill every four weeks. This method
improves color without turning the white parts of your fish pink.
Add some more variety by feeding live foods. Koi naturally
eat crustaceans, insect larvae, worms, and aquatic plants in the wild. Live
plants offer fish roughage and some necessary vitamins and minerals. Just
remember that these supplemental foods should complement Koi diets but never
replace nutritionally balanced staple or maintenance foods.
Once water temperatures are consistently above 60 degrees in
the spring, start feeding your fish wheat germ sticks. At 70 degrees and above,
switch to staple foods. For a couple of weeks at this point, you may want to
start out with Koi growth foods that contain higher protein and fat levels. Not
only do these foods help younger fish grow quicker but also help established
fish combat low energy reserves from not eating all winter.
In the fall, just follow the spring feeding schedule in
reverse. Besides watching your pond thermometer, you will know to make the
change when your fish start spending more time near the bottom of your pond
where it is warmer. As temperatures get lower for the winter, so do Koi
metabolisms. Transition Koi to a lighter diet by mixing wheat germ sticks or
pellets to regular Koi staple foods or purchasing blended diets that already
include wheat germ sticks. Once temperatures fall below 60 degrees, switch
completely to the wheat germ diet, and, below 50 degrees, stop feeding the fish
altogether for the entire winter to avoid food decaying in their systems.
Store foods in airtight plastic containers to avoid moisture
and in a cool, dry place away from sunlight. Koi food loses its nutritional
effectiveness if kept too long and even faster if exposed to sunlight and heat
choosing the right Koi food keeps your fish and your pond ecosystem healthy and
allows your filtration system to work efficiently and maintain clear water. If
you spend a little more money up front for quality food, you will save on
maintenance time and costs throughout the season.