Wheatgerm is a type of fish food that is ideal to feed to your fish in winter, or at temperatures down to 6°c.
It is a food source rich in complex fats, vitamins and minerals. It also contains slow releasing carbohydrates. These are the essential elements that your fish need in there diet to remain fit and healthy during winter.
Wheatgerm is very easy for your fish to digest even, when there metabolism has slowed to a crawl and they are becoming more dormant.
Feeding can be reduced to daily rather than, twice or three times daily. The quantity that your fish consume may also be less compared to what they were consuming during the warm summer months.
Even if your heating your pond unless the temperature is maintained above 12°c I would recommend using wheatgerm food. But i would stop feeding completely if the temperatures drops close to freezing.