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Pond Heaters and Pond Deicers - Ways to Deice a Pond

Pond "Heaters" and Pond Deicers

Use a pond deicer or pond "heater" to heat a small opening in the top of your pond where it normally would freeze over in the winter.  By having a deicer you will keep an area thawed in the pond's surface, thus providing an 'exit hole' so toxic gases from decomposing organic matter can escape and oxygen to enter your pond.  

Pond deicers are not heaters.  They will not "heat" your pond.  They have automatic thermoregulators inside of them and turn on when the water temperature is around 40 - 44°F. The "heat" generated by the de-icer will keep an area of the pond's surface from freezing, thus allowing a hole for toxic gases to escape and oxygen to enter.

Use a pond aeration system during the winter to provide oxygen to the fish since your pumps, waterfalls, and fountains will most likely be turned off which was the source of oxygenation during the warmer months.  For those of you with large ponds, you can use your large aerator all year round, even in the winter which has many benefits:

  • It continues to add oxygen to the water,
  • continues to help break down organic matter within the pond,
  • and keeps an area of the pond open from a solid piece of ice forming over it. 

Use Microbe-Lift® Autumn Prepto add beneficial bacteria during the fall and winter to continue tothe decomposition of organic matter (leaves, fish wastes, sludge, silt, etc.). This will give your pond a great head start for the spring and works in cold temperatures below 55°F.  (A lot of products on the market only work with temperatures above 55°F).                 

If you're looking for a deicer to prevent the formation of damaging ice around boats and docks, we have boat and dock deicers those too!   

A little information about the different deicers and how to determine which one you may need:

A floating pond deicer will keep an area of the pond's surface open during the winter. When water temperatures are colder than  40 - 44° F, the unit will turn on and therefore start to "de-ice" or heat an area and keep it from freezing. Because it floats around, it can therefore keep a nice size of the pond's surface open. Adding a thermo cube (product code FITC3) will add more energy efficiency to the floating deicer because it senses air temperature instead of water temperature. If the air  temperature is above 40°F or so, then it should be warm enough to start melting some of the ice on the top of the pond. The thermo cube will then turn off the floating de-icer so you save money on your electric bill.  (The movement of an aerator providing oxygen and some movement to the water also helps to keep an area of the pond open as well).

A submersible pond deiceris thermostatically controlled just like the floating deicers except there are different variables in regards to temperature.  Since the submersible ones sit on the bottom of the pond, pond depth has an important role.

The surrounding soil from an excavated pond acts as an insulator to the water, and therefore keeps the water temperature of your pond from freezing.  This occurs at depths of about 3' deep and deeper. The soil temperature at that depth doesn't go below approx. 40°F (unless you live in the artic) so the surrounding soil acts as an insulator to the pond water. Since the soil temperature doesn't go below 40°F at 3'+ depth, neither will the water at the bottom of your pond.  If your pond is 3' or deeper, you wouldn't need a submersible deicer but a floating one. If your pond is shallower than 3', then you could use either a submersible one or a floating one (or a convertable one). The floating one pretty much guarantees that an area of the pond's surface will be open. A submersible one does not.  It's just if you want to "heat" the bottom of your pond, too. So what is at the bottom of your pond that you would want it "heated"?  Well, fish are in the pond for some people while others have plants. The submersible deicer will help to keep the fish from freezing but small fish at 5" or smaller should be brought indoors.  They don't have enough fat on them to insulate their bodies and keep them warm during the winter and may die. Larger fish will often "hibernate" around the submersible deicer as even 40° F gets mighty cold but at least they have some fat on them to keep them warm. Hardy aquatic plants should have been prepared and placed in the deepest part of the pond, preferably around 3' deep in order to survive the winter. 

For those of you with above ground ponds, we recommend you bringing the fish, etc. inside during the winter.  If you absolutely cannot do that, then the best thing would be to try to insulate the pond itself by stacking some bales of straw around it in addition to using a submersible deicer and an aerator.  Keep checking the pond during the winter to see if part of the pond's surface stays open.  Remember, the outside of your preformed pond needs to be properly supported with soil or some type of frame work since the plastic could crack with freezing and thawing temperatures.  By adding the straw bales outside, it will help keep it from cracking due to thermal shock.

Good luck!  :o)