December winter prep

Even as the temperatures drop
into the 30s, the Koi Garden
still teems with life.

An early morning walk through
the garden allows time and
the light to find some small,
busy neighbors.










The winter die back allows for the Koi Garden to shine in other ways. It does make the fall/winter cleaning worthwhile.


In the northwest, filter temperature is a constant problem. I use a small aquarium heater placed inside the filter assembly to help keep the filter working.


The heater keeps the temperature above 50 degrees, measured in the pond at the alternate corner. This allows the fish to feed earlier in the spring and longer into the fall/winter. Koi go dormant at temperatures under 40 degrees and should stop feeding under 50 degrees. When the temperature bounces over and under that 50 degree level and you are still feeding your fish, there is a chance that the Koi will not be able to process the food, thereby getting very sick. By using a heater, you can help remove this risk as the transition through feeding and letting the fish go dormant a lot easier. Also, in the spring, as the temperature is rising again, the harmful bacteria and viruses wake up from dormancy faster than a Koi's imune system. Having a filter heater can help make the transision from 30s and 40 to over 50 a lot smoother.
It also allows the filter to remain at a higher temperature allowing the beneficial bacteria to work more efficiently. Since the pond temperature is now falling close to 50 degrees and the outside temperature is mostly well below it, it is time to turn the heater off for the winter. The Koi will be fine as long as the pond doesn't completely freeze over.
I prefer to turn the heater off at the plug in, rather than remove it from the filter. This allows me the option of turning the heater on for a few days if the pond start freezing over in a cold snap.

In preparation for the winter, I also put the winter screen on the pond. It is a wood framed monstrosity that has a metal screen that I built a few years ago. This allows light and all the elements like rain to get through, while keeping the raccoon away. I don’t use this screen in the summer or while I am around and enjoying the Koi Garden, but in the winter, it is a nice way of keeping predators at bay.