Sierra Water Gardens
Fall/Winter Care for Ponds and Koi



Stay on top of leaves and other falling autumnal debris. Use a skimmer net with telescopic handle and frequently empty out your pond skimmer. Leaves that are not removed from the pond become toxic to fish as they decompose and release tannins into the water during the winter. Do a water change, and even a full cleaning if necessary, to maintain good water quality during the winter.



Know Thy Pond Temperature! Once your pond falls between sixty-two and sixty degrees begin preparing your koi’s digestive system with WHEAT GERM food. Once your water reaches fifty degrees, stop feeding your koi entirely.


ICE (isn’t so nice)

Use a floating pond de-icer or an air diffuser to maintain a hole in the ice. The hole is important for exchange of gases, releasing toxic gases and taking in oxygen. Running your waterfall during the winter can make the pond colder than it needs to be, but many pond keepers do find success in keeping the pump running. If your pond does freeze completely, DO NOT BREAK THE ICE! Shock waves pulsing through the cold water can be fatal to your peacefully dormant fish.



ProForm-C your pond.  As your koi enter dormancy, so too do the parasites they carry. As your koi wake up during the spring, the parasites wake up with them but the koi’s immune system is not fully functioning in the still cold temperatures and it is difficult for them to fight off infection. Use ProForm-C before your pond reaches 52 degrees and keep up with KoiZyme until 50 degrees, increasing the dosage as your pond decreases in temperature.



Cut your lilies down 1" from the tuber and leave any small new growth and cut back your hardy marginal plants after a couple frosts and sink them to the bottom of your pond. Hyacinths and Water Lettuce make great compost after they die in the first frost. It is important to get any dead or decomposing plants out of the pond before winter.



Remove your UV Light and store safely until next season and drain any external bead filters.

Oil filled pumps need to be stored in a bucket of pond water to prevent the seals and gaskets from drying out, while you can store a mag-drive or epoxy pump dry.



Remember: You do not lose all of your beneficial bacteria when your turn your water off during the winter. At the most, you’ll lose between 70 and 80 percent, but you still have 20 percent that will regenerate rapidly during next spring.