Whether you have a small koi pond or a large fishing pond, it’s important to consider what your fish need to survive during the cold winter months. Temperatures that creep below freezing put your pond at risk. If your pond freezes over, it can be damaging, if not fatal, to your fish population. Here’s how to avoid a frozen fish pond so you can keep your fish alive and well during the winter.
Here’s How to De-Ice Your Frozen Fish Pond
First off, it’s worth mentioning that if your pond does not entirely ice over in the winter, then your fish are not at risk. The only danger comes from a frozen fish pond that has completely iced over. In this case, all of the waste and CO2 produced by your fish population has nowhere to escape which results in reduced oxygen levels and increased water toxicity levels. The net result is a pond that is too poisonous for your fish to survive.
If your pond only freezes over for a day or two, your fish should be fine, but if the entire pond surface is frozen for more than a few days (or even weeks), you’ll need to take measures to break the ice. That being said, even a small opening in the ice can be enough to allow CO2 and waste to escape. Here are a few things you can do to de-ice your pond and keep your fish alive during the winter.
Use the Hot Water Trick
For smaller ponds or koi ponds that ice over only occasionally during the winter, you can use the hot water trick. It’s exactly what it sounds like—simply boil water and pour it onto the ice until the ice melts away and the water becomes exposed. Of course, this works best in smaller ponds that do not ice over regularly. For larger ponds, or ponds that stay frozen for long stretches of time, this method would become too cumbersome.
It’s also worth mentioning that this is the least stressful method of de-icing a pond for the fish. Do not attempt to chip away at the ice with a chisel or axe. The sound and vibration in the water can be stressful for the fish.
Get a De-Icer
For larger ponds that freeze over more regularly, it might be good to invest in a de-icer. These electric heaters can be placed in your pond to warm the waters around it. As a result, your pond will not ice over in the area in which your de-icer has been placed. This will leave room for wastes and gases to release from the water during the winter. However, because de-icers work only in a limited area (so as not to change the overall temperature of your pond), extreme cold can cause the area over the de-icer to ice over, resulting in a warm bubble that forms around the de-icer.
Get a Pond Aerator
Used alone, or with a de-icer, your pond aerator can help you avoid a frozen fish pond. Because aeration systems move oxygen through the water and expel any wastes or gasses to the surface, they usually do a good job of keeping parts of your pond free from ice. However, make sure to place the aerator about a foot from the bottom of your pond. If it is too high, it can pump cold water into your pond, and freeze your fish in the process.
BTL Liners makes custom geomembrane pond liners that can contain your fish pond year-round. Our liners can withstand temperatures as low as -85 degrees Fahrenheit (for BTL-24, BTL-30, and BTL-40) which make them perfect for climates that experience extreme weather conditions during the winter. Contact us for more information.