Pond Heater in Your Fish Pond?

Using a pond heater for fish ponds is not necessary in the average home koi or fish pond if there is enough depth to stop the water from freezing straight to the bottom of the pond. In other words, if the pond is deep enough the water doesn't freeze to the bottom, then you do not require a pond heater.

In severe climates and shallow ponds, the recommended solution is to bring the fish into the house for the winter.

If you want to leave the fish in the pond over the winter, most people want to maintain a small hole of open water for oxygen exchange. Even though the fish are pretty much dormant down there, decomposing foliage can give off gases that can build up and kill off fish.

Small Heater Option

Having said that. There is a small heater, often referred to as a stock-tank heater because it is used by farmers to keep watering troughs open, that floats on the surface of the water and will keep a very small hole open through the coldest winter.

These are readily available on the Net or through a farm-supply store.


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Larger Units

Larger heating systems for the dedicated, cold climate, fish ponder involve hooking up a swimming pool heater to the pond. These are available from a local swimming pool dealer. While I have never used such a system, I-m told it works well but the plumbing should be set up to bypass it in the summer so as to keep it fairly clean during the "dirty" summer months.

Two Other Options

Another alternative that is inexpensive and does not involve purchasing other supplies is to disconnect your pond pump from the filter, put it the lowest section of the pond and turn it on. The water flow will keep a section of water ice free. Adding a discharge pipe that points straight up is a preferred way to keep the water free in very cold climates.

You can also use an air bubbler system to keep a hole in the ice. Do not use an air stone with this system, your objective is to roil the water in one place, not to add multiple air bubbles.

In short, those are your options if you keep the fish in the water overwinter in cold climates.

Shopping Resources for This Article

Stock-tank heater

Air bubbler system

Swimming pool heater