Pond pumps and filters can be kept yearround in a place that experiences mild winters, however, in colder places, it may save your equipment to remove it before the first freeze. You'll want to keep using your pond filters while you're still feeding your fish so that they can remove the excess food and waste associated. Once you stop feeding your fish (usually once temperatures in the water drop below 50 degrees), you can remove your pump and store it somewhere it wont freeze in a bucket of water. Keeping the pond pump wet is important so that its rubber seals don't dry out and crack, ruining the pump.
Most pond pumps and filters will have a listed minimum operating temperature in their user's manual or on their manufacturer's website. Use this as a guideline for the best time to remove your pond pump from the water.
