Winter is coming…
With the days getting shorter and the air getting colder winter is well on its way, which means your pond will need a little maintenance to ensure it will look good throughout the winter and your fish have no problems during the colder months.
Plants
Before winter really sets in it’s worth going round your pond cutting back any dead vegetation left over from the summer. This will help to reduce the amount of organic matter entering the pond during the winter which will, in turn, reduce the risk of any water quality problems in the future. It will also make your pond look much tidier.
Any hardy water lilies you have in your pond should be moved to deeper water and any non-hardy lilies, such as pigmy lilies, should ideally be removed from the pond and placed in a large container of water and stored somewhere away from the cold, such as a garage or garden shed.
Fish protection
Being cold blooded creatures, fish will start to enter a semi dormant stage with the onset of winter becoming a lot less active and feeding less frequently. As the temperature of your pond reaches around 10-12oC you should switch to a good quality wheat germ feed for your fish and reduce the frequency and quantity of their food. Any uneaten food should be removed from the water.
Once the water reaches around 7oC the fish will stop feeding completely and will enter their semi -dormant stage, spending most of their time in the deeper areas of the pond where the water is likely to be slightly warmer.
It is worth moving your pond pump and the out flow from your filter to ensure this layer of warmer water in the deeper areas of your pond is left undisturbed; alternatively you can reduce the flow on your system. Whatever you choose to do, mixing the colder upper layers of water with the warmer deeper parts should be avoided.
Ice can be a problem in the depths of winter; a solid layer of ice will stop the exchange of gases in your pond, preventing oxygen entering the pond and stopping the carbon dioxide produced by the fish from exiting the pond. Pond heaters are available but these only raise the water temperature by a few degrees and are expensive to run, instead it is better to keep the surface of the water moving by keeping your pump running throughout the colder weather or by placing an air stone in your pond.