The quantity of food required by pond fish is largely dependent on the water temperature. The lower the temperature the less they will consume, they will feed down to around 5C. However, they will require far less than they normally eat, so feed them sparingly and remove any excess. When feeding the fish in the winter and the water temperature is below 10C (50F) then the fish should be fed an easily digestible wheat germ food. If the water temperature drops below 5C then it is probably not worth feeding them at all.