Shutting Your Pond Down For Winter

The steps you take to properly shut down your pond in the fall for winter will determine the quality of your pond water and the health of your koi and pond fish in the spring. Plus, it could be the difference between losing fish in the cold winter months or not.


Shutting your pond down in the fall is not set to an exact date; it all depends on the temperature of your pond water. Some fall seasons are much warmer than others and your pond water will stay warmer longer, some fall seasons are colder and your pond water will cool down earlier.

A rule of thumb is to shut your pond down for the winter when your pond water drops below 50 degrees F and stays at that temp for 10 to 14 days 


Stop any feeding of your fish for the entire fall/winter season when your pond water drops below 55° F and stays there for ten to fourteen days, day and night. Once you stopped feeding for the fall/winter season, do not feed your fish  even if your pond water temperature rises.


There are two major reasons why you stop feeding your fish when pond water temperatures drop below 55° F:


1- The metabolism of your koi starts to slow way down with pond water temperatures below 55° and your koi can not digest their food. Your koi do not have a stomach, just a long intestinal tract; the food lays in their digestive tract and rots, causing death.


2- Even if your koi could digest their food at colder pond water temperatures of 55° or below, their waste would produce deadly ammonia in your pond water. Plus, feeding your koi below 55°F will cause your ammonia levels to rise because the "Good Bacteria" that removes the ammonia from your pond water keeps slowing down under these cold water conditions and eventually stops functioning. DO NOT feed any kind of food with pond water temperatures under 55°F


When you stop feeding, shut off and drain all your water pipes, filters, U.V.s and pumps to prevent freezing and cracking. Leaving the cold water in your pond circulating around your fish will reduce their body temperature. The best solution is a pond aerator, and add a de-icer if your pond is susceptible to freezing over.