If you live in a warm climate your Koi pond can stay active all, your but if you are in the north you need to learn a bit about winterizing your Koi pond. Yes, your pond can survive the winter if it is deep enough for water to exist below the frost line.
When it gets to be near winter, you want to do some basic pond cleanup to get your pond ready for the next season. Get rid of any unwanted plants both in the pond and around it. Rake the leaves and get rid of any other things that you don’t want there like rocks or sticks and twigs. This is a good time to dig up any of the plants that can’t survive the winter and move them inside. Clean up debris that could be blown into the pond over the winter - you might even consider a pond cover to keep it clean all year.
Once the temperatures fall below 50 degrees, your Koi will go into “hibernation” mode and stop eating so you must stop putting good into the pond or it will decay and cause your water quality to degrade. Once the temps start to drop, you want to feed the fish less and less - never feed them once it gets below 50 as they will not be able to digest the food and this will be very harmful to them.
Another step in winterizing your Koi pond is to make sure all the equipment is in good working order. Check your filters and pumps. Also, stock up on any chemicals or medicine you might need for the pond in case your garden store closes down for the winter and you cannot resupply. Make sure you have all your testing stuff, nets, and medications handy for the winter season.
Koi can live in temperatures to 39 degrees so if your pond is deep enough to still have running water, you should be OK. If not, you might consider a heater. If you do buy a heater, then be sure to get one that is appropriate for the size of your pond. If you want, you can always remove the fish from the pond and put them in a tank inside your house for the winter months.
Winterizing your Koi pond is an important step in insuring that your pond remains in good working order all year long. Do the prep work before winter starts and your pond will be ready to go come spring!