Koi pond water, when the weather turn cold, will need a bit of extra maintenance in preparation for the colder temperature. Consider the below preparation instructions in order to give your koi fish the best chance for surviving the winter months.
Prepare Your Pond
Before it gets too cold, prepare for winter by cutting back plants, cleaning filters, turning off pumps, and draining the pond. Cutting plants or removing them from the water guards against the ammonia that could get trapped under the ice as temperatures drop and the plant's leaves decay. Cleaning filters and draining the pond ensures that your fish have the most oxygen-rich water supply before finally turning your pumps off.
Change Feeding Strategies
If you continue to feed your fish the same amount as in the summer, you will have excess nutrients in the water that can give off dangerous gasses as they decay. By feeding fish in small amounts a few times a day, you will see how much the fish are really eating and avoid potential problems. Switching to a wheat germ based food that is easier for your fish to digest is also a good idea.
When to Take Emergency Steps
For ponds that are more than 18 inches deep, koi will find the deepest parts and stay in them until the freeze is over. It is not necessary to remove fish from a pond unless there are no places for the fish to escape the weather. If you are concerned your fish aren’t getting enough oxygen, thaw a section of your pond with hot water to create an air vent, In addition, if you think your pond is too small to withstand a harsh winter, the last resort is to move fish to a small indoor pool for the winter. Make sure that you have sufficient filtration and aeration for the fish to survive in the pool.