If you're fortunate enough to live in a warm climate, your pond can stay active all winter. However, if you live farther north, you're going to have to do a little bit of preparation in order to ensure that your pond survives. The most common problem for Koi ponds during the winter months is aeration. Here are some easy steps to winterize your Koi pond.
First get rid of any leaves or debris that has piled up on the bottom of the pond. If these are left for the winter, they'll start to decompose and pollute the water.
Once that's done, there are a few options in how to winterize your Koi pond. First and foremost, always make sure you break holes in the ice so that oxygen can enter the pond. The best way to ensure that the pond never freezes over completely is to buy a small floating heater.
Many people take their pumps inside for the winter to keep them from freezing and breaking. If you decide to do this, you still have to make sure you pond is aerated. There are fountain kits available that create surface disturbance so the water doesn't stagnate during the winter months.
If you choose to leave your pump running, you simply have to make sure it doesn't freeze and that there's enough water to run it. However, since water doesn't freeze if it's moving fast enough, you can put your pump near the surface (but below the ice). If you choose this option, make sure you place plenty of rocks or pots or other decorations for you fish to hide around so that they're not stressed by the current in the water.
Aquascape stainless steel Pond De-Icer is ideal for keeping a small hole opening the ice during cold winter months, and insures proper gas exchange helping keep fish alive during the winter.
It is important to leave a small hole open at the surface of the pond allowing for necessary gas exchange. In extreme conditions or gardening zones above USDA zone 5 we recommend the deicer be used in conjunction with an Aquascape pond aerator.