When it comes to caring for your pond fish during the winter there are a number of things you need to check before the weather turns cold. If your pond is less than 20 inches deep, it is at risk of freezing and with it your pond fish. You need to ensure that your fish have plenty of water to swim in, even if the top of the pond might freeze after a particularly chilly night. Over the winter, your fish will eat very little. This is because the temperature of the water in your pond controls their metabolism. They will not be as active as they are usually in the summer. During the summer, pond fish need plenty of protein to keep them active. This is obtained through the fish food that you will be putting into the water. However in the winter they do not require as much protein, which is why specialist winter food for your fish has been developed. This specialist food contained wheatgerm, which contains all of the nutrients that your fish will need to survive the winter months.