Water Garden & Features Q & A
Q: How do I prepare my fish for winter? Do I need to bring them inside? – Liz in Michigan
A: As the temperatures fall, we may be pulling out our winter coats and goulashes, but your fish don’t need them at all! In fact, pond fish, like koi and goldfish, do quite well in a pond over the winter – even if it freezes over – as long as your pond is at least 18 inches deep (though we recommend 24 inches to be certain the fish don’t turn into popsicles). The fish will go into their annual torpor, or dormancy, and will require little more than clean, oxygen-rich water to survive.
To ensure they get that life-sustaining oxygen, you will need to do four things:
1. Remove debris from the pond. In the fall, before ice forms, give your pond or water feature a good cleaning. Rake out debris, trim dead leaves off plants, net floating leaves and remove as much detritus as possible so very little will be decomposing – and releasing harmful gasses – through the cold months.
2. Add some beneficial bacteria. Also in the fall, you may want to add some beneficial bacteria, like Pond Logic®’s Seasonal Defense®. It accelerates the decomposition of leaves, scum and sediment that builds up during the fall and winter months. In the spring, it replenishes winter bacteria loss, jump starts the filter and breaks down unwanted waste, making your pond water ready for a clean spring and summer.
3. Install an aerator or air stone. Colder water holds more oxygen than warmer water, but you’ll still want to inject air into the pond during the winter months, especially if your pond freezes over. One or two air stones or a diffuser placed in a shallow part of your pond will be enough to aerate the water and keep a small hole in the ice, which will allow harmful gasses to escape and oxygen to enter.
4. Hook up a heater. If you live in a frigid area where the ice on your pond builds to an inch or more, you can use a floating heater or de-icer, like the Thermo Pond, that melts through the ice. Again, it’s critical to keep an open hole in the ice to allow for gas exchange.
In most cases, your fish will be just fine through the winter months. When the water warms, you can begin feeding them again and enjoying them for yet another year!
POND TALK: How do you prepare your fish for winter?