Maintaining Koi fish is an excellent outdoor pond hobby and the one aspect of this hobby that we often take for granted is their feeding. Koi don’t have stomachs and hence require feeding at regular intervals. Also, not having stomachs means they have no way by which they can store nutrients. Koi, when kept outdoors, have a wide range of food like insects, larvae, plant and algae matter to choose from.
While these food items can be more nutritious in comparison to the prepared food that we feed them with, we can’t just rely on these foods alone for their overall nutrition. For these food items can at best act as supplementary diets that will keep the fish going in between feedings. This also allows you the luxury of leaving the fish attended for a few days; say when you are on a short vacation.
However, it’s best when Koi’s are fed several small meals each day to ensure proper digestion and proper nutrition. Koi’s being temperature sensitive, their feedings depend on the ambient temperature. So when temperature is below 60° F, koi’s will require only a few feedings per week and with temperature falling below 50, just one or two feedings per week is all that is needed.
Coming back to temperatures, koi’s have been found to be not able to digest food well enough in colder temperatures. What this means is that koi kept in northern climates need special care while feeding, more so before and after the hibernation season. Their metabolism slows down considerably when water temperature begins to dip below 45° F, so much so that their ability to digest can become severely restricted. During this time, any excess protein stuck in their digestive tract can lead to infection, something that should be avoided during the hibernation season.
So its best to go for a wheat germ based diet that is low on protein when temperature drops to below 50° F during the onset of winter and also during spring when temperature starts to climb above 45° F. Once the temperature is back to above 50, the staple diet having normal protein content is what the koi’s will need and a protein rich diet once temperature rises to above 65° F.
Though not as important but pond fish feeding demands enough attention in the warmer areas as well. As temperature begins to rise, the quantity and frequency of feeding should rise as well.
There may be koi’s of various sizes and their food requirements may vary, which may leave you confused as to how much they should be fed with. Trying the one-minute rule of feeding can help solve this since after a minute of feeding, there should be no excess food remaining. It may require several feeding sessions to perfect this and is something that is sure to vary as the season progresses, particularly so when the koi’s are growing.
Its more likely that they will be fed more than what they require and may seem to have a perpetual hunger, something that can be attributed to their trained response to your presence than their actual requirement for food.
Though they will consume as much food as is provided to them, it should be noted that they will digest only what they are capable of and the rest simply passes through their system.
These unused food are of no help except providing an excellent setting for algae and weeds to thrive on.