Great info here from Tetra Pond Products!
As water temperatures begin to fall in your area of the country, it is important to transition your pond fish to a highly digestible wheat germ-based food. Because fish are cold-blooded, their metabolism is controlled by the temperature of the water. So as water temperatures start to dip, you’ll need to make some changes to your fishes’ diet.
In water temperatures between 39°F and 50°F, wheat germ is ideal to transition fish into the cooler winter months because it digests easily at low temperatures. This is especially important because in the winter, fish metabolism and the pond’s ammonia-reducing biological activity are greatly diminished. And remember, never feed fish when water temperatures fall to 39°F or below. In addition, feed your fish only as much as they can eat in several minutes. If you are able, it is best to feed smaller amounts several times a day, versus one large feeding (not unlike how humans like to eat).
For optimal nutrition, TetraPond Spring & Fall Diet transitions fish in and out of the season and reduces thermal stress. That’s important for disease prevention.
Seasonal Feeding for Year-Round Nutrition
Follow a Seasonal Feeding Cycle so you can easily determine the best foods to feed throughout the year as indicated by the water temperature. When you use a TetraPond Thermometer , you’ll eliminate all the guesswork in fish nutrition.