Do you wonder what the koi do during the winter?
It’s Called “Torpor”
Fish go into a dormant state during the winter called “torpor”. They may look like they aren’t moving at all, because they aren’t. They will conserve calories and stored fat by not moving. It is similar to hibernation.
Fish often put themselves very close together, all facing the same direction. They usually do this at the deepest part of the pond. They just stay that way, barely moving at all. They may do the same thing in their fish cave.
Koi During the Winter – The Big NapBoth koi and goldfish exhibit the same winter behavior. They are basically just taking a nap while waiting for the seasons to change.
Sometimes fish can be seen through the ice or when the water is not frozen. Occasionally, it may look like they are frozen in the ice, but unless your pond is 7 inches deep, they are not.
Can fish freeze into ice and be fine later?No. Someone asked this question, so I will clear it up for anyone who might be wondering. Neither goldfish nor koi can freeze into a block of ice and then thaw out in the spring, with life suddenly surging into their colorful fins once again.
Ice on the top of the pond insulates the pond! Believe it or not, the fish are warmer and safer with ice as long as there is a hole for gasses to escape.
Kristi’s Pond Tips
Remove floating plants for the winter.
Net out leaves that weren’t captured by the pond skimmer.
If the system has low flow, figure it out before the brutal cold of winter has really set in.
Add cold water bacteria weekly to keep it looking good through the warm and cold spells of a Colorado fall.
Don’t feed the fish when the water temperature is 50 degrees or less. If you are uncertain, don’t feed them.
More resources: I found THIS from Fitz’s Fish Ponds about fish being dormant in the winter. If you want to know more about Koi During The Winter from Colorado Pond Pros, search for any topic in the search bar below. Premier Ponds wrote a nice article on this too: De-Icers For Ponds And How They Can Save Your Fish
It is so important to take care of your backyard pond during the cold, Colorado winter months. If you need any help with pond repair, installation, or cleaning services, give your pond experts a call. And Colorado Pond Pros is your solution to all questions about winterizing your koi pond!