Each fall, as water temperatures decrease, fish metabolism slows down. They become less active and their need for food decreases. Most pond owners observe a gradual, but noticeable, change in their fishes’ behavior when the water temperature cools below 65°F. The fish gradually start swimming slower and become less interested in food.
It’s important to check your pond’s water temperature because as a fish’s metabolism slows down, they aren’t able to effectively digest the rich proteins found in most summer foods. Although, fish will eat summer food in cold water, they aren’t able to digest it correctly and can’t ‘bulk up’ properly for the winter. If you feed a summer food in cold water, much more waste is produced by the fish which can have a negative impact on water quality.
When the water temperature falls to 60°F or below, begin feeding a quality Spring & Fall / Cold Water Food. At Holly Days, our pond & aquatics department offers two premium cold weather foods, Hikari and Tetra. A proper cold water food will have wheat germ listed as the first ingredient. Koi and goldfish can digest wheat germ very easily, especially in cold water. We recommend gradually transitioning koi and goldfish onto the cold water food by mixing it with their summer food and then gradually increase the amount.
As the temperature falls further, gradually cut back the amount you feed your fish as well as the number of times per week you feed them. At around 55°F feed your koi no more than once every other day. Once the temperature remains below 50°F you should stop feeding altogether. Although, fish may still eat food below this temperature, it can often do more harm than good as the bacteria in their digestive system stops functioning.
Knowing the water temperature of your pond is very important, especially this time of year. If you don’t have a pond thermometer floating in the pond, get one! It is the best investment you can make for happy and healthy fish & pondlife.