Your garden pond also needs the proper care in winter. While fish, other animals, and water plants go into hibernation, you must ensure that the garden pond remains ice-free in winter. Even if they are “cooking on the back burner,” the animals and plants in the pond need enough oxygen. You do not have to keep the entire pond ice-free. It is enough to keep some spots ice-free. You don’t need to feed the fish in winter, as they live off their reserves.
Why You Should Keep Your Pond Ice-Free
To enjoy your pond and fish again in the coming pond season, you need to keep the pond ice-free. Sensitive fish cannot stay in the pond over the winter. They must overwinter in milder temperatures and warmer water. If you keep native or hardier fish, these fish can remain in the pond without any problems. However, these fish need sufficient oxygen to do well through the winter.
It would help if you also kept the pond ice-free to avoid damage. A pond pan can crack if it completely freezes over. A pond liner can also be damaged if the pond completely freezes over. The pond will then lose water in the coming season when the ice has thawed.
The options you use to keep your pond ice-free depend on the pond’s size and how long the freeze will last.
The Gentle Way – Ice-Free With Water Plants
If the pond is less than 30 inches (80 centimeters) deep, the most significant risk is that it will freeze over completely. Under no circumstances should you smash the ice with a hammer or ax. In doing so, you run the risk of injuring or killing the fish. The pressure waves could burst the fish’s swim bladders.
A natural and gentle method is to use hardy evergreen aquatic plants. Well suited are
- Eurasian watermilfoil
- golden mace
- water lilies.
The aquatic plants provide oxygen and ensure that the pond does not freeze over completely. These plants cope well with sub-zero temperatures because they are native. During icy and long periods of frost, your pond may freeze over despite the plants. You will then need some extra help.
Plants in the shore or shallow water zone that stick out of the water also help keep the pond ice-free. Frogspurs, hedgehog bulrushes, or water irises are suitable.
A Rubber Ball or Piece of Wood
You can also keep your garden pond ice-free by using a rubber ball or a piece of wood. You need to place the ball or piece of wood on the water surface. To keep your garden pond ice-free, you will need to regularly douse the rubber ball or piece of wood with warm or hot water. This may be necessary several times a day. Where the object floats, your pond will not freeze over.
Tip: Take fish out of a very shallow pond.
If your garden pond is very shallow and you want to keep it ice-free with a rubber ball or a piece of wood, you should remove the fish for safety. You can overwinter them in a rain barrel and a frost-free cellar or heated garage.
Ice Freeholder With Sink Chamber
The trade offers a range of aids with which you can keep your pond ice-free. Ice freeholders with countersunk chambers are offered in different sizes. When buying, you should make sure that you can use these ice-free holders at minus 4 degrees Fahrenheit (minus 20 degrees Celsius) temperatures.
It would help if you chose the ice-freeholders depending on the size and depth of the pond. The sink chambers are located in the water. With a heater inside, the sink chambers are heated. The heat is transferred to the surrounding water. The ice around the ice freezer melts. New ice cannot form.
The ice-freeholders have venting channels on the sides to ensure a constant oxygen supply for your fish. A pump transports warm water from the pond to the top. The heater prevents the pump from freezing. The water conveyed to the top absorbs oxygen. Digester gases can escape. To prevent the ice freezer from buoyancy when ice forms, the sink chambers can be filled. They can be filled with pebbles, for example.
You should regularly check whether the ventilation slots are free. You should remove any impurities.
If there are fish in your pond, you should place the ice-freeholder at the deepest point of the pond. It can consistently warm the water to a specific temperature there. It would help if you anchored the ice-free holder so that it stays in place.
DIY Ice Freeholder
With a bit of craftsmanship and joy in tinkering, you can build the ice-free holder yourself. You need
- five polystyrene plates, which you buy depending on the size of your pond
- two pipe bends with angles of 90 degrees
- vent pipe.
You cut out rings from four polystyrene plates that should have a diameter of about 20 inches (50 centimeters). From the fifth plate, you should cut out the appropriate cover. It should have a diameter of 12 inches (30 centimeters). In the center, drill a hole for the vent pipe. It would help if you glued the rings and the lid together. Use the two pipe bends to fix the vent pipe in the lid.
You can also use rigid foam to build your ice-freezer. A white rigid foam core with a medium pore size serves as a floating base. The rigid foam block should be 20 to 24 inches (50 by 60 centimeters) in length and 4 inches (10 centimeters) thick. In the ice-freezer center, make an opening into which you will insert a 24 inch (60 centimeter) long pipe. It would be best if you used a sewer pipe with a large diameter for this purpose. Fix the pipe in the opening with silicone. The vent pipe should be about 12 inches (30 centimeters) in the water. You can prevent the pipe from freezing by placing a vent stone at the bottom.
The Reliable Pond Heater
During more extended periods of frost, a pond heater does a reliable job. It works similar to an immersion heater and has afloat. The pond heater keeps the ice-free float area at temperatures down to minus 4 degrees Fahrenheit (minus 20 degrees Celsius). When it freezes, the pond heater turns on by itself, while it turns off again when the temperatures become milder. For this purpose, the pond heater is equipped with a frost monitor. Thanks to this automatic temperature control, you save electricity with the pond heater. The operation is straightforward.
A pond heater has a simple design. It has a heating rod, which is covered with styrofoam. This heating rod rests on top of the water. If you invest in a higher quality pond heater, there is a flow pump. It provides for water movement. The pond heater does not endanger the fish.
A pond heater is suitable for ponds with different depths.
Ice-free With the Pond Heater Cable
Similar to a pond heater, a pond heating cable works. However, it is more expensive and consumes more electricity. It is suitable for koi ponds. Such a heating cable has sheathed copper wires. It can be laid on the bottom of the pond and remain in the water permanently. A thermostat can control high-quality cables.
You can place sensors in the pond to measure the temperature. Overshooting of the heater after switching on is prevented with a start-up circuit on the controller. If the sensors are short-circuited, the heating is switched off. The fish are not endangered. An LED lamp indicates a failure of the heating cable. To prevent heat loss, you can use bubble foil as a pond cover, especially during cold and long frost periods. It would be best if you poked holes in the bubble wrap for sufficient oxygen supply.
Ice-free With the Frost-Proof Pond Pump
A frost-proof pond pump works reliably and keeps the water constantly moving. Such pumps are offered in different power levels, which you can choose depending on the size of your pond. With a pump, there is always an adequate supply of oxygen. The water is heated as it passes through the pump. As a rule, the pump does not run day and night. It is, therefore, more suitable for less harsh winters.
Preventing the Formation of Putrefactive Gases
You can prevent the formation of foul gases by thoroughly removing dead branches and leaves from the pond in the fall. If the pond has not frozen over, you should check it regularly for such contaminants and remove these contaminants.
What to Do If the Pond Does Freeze Over?
Now, in freezing temperatures and more extended periods of frost, it can happen that your pond does freeze over. With simple methods, you can get the pond free of ice again. You should boil water in a pot and place the pot with the hot water on the ice. If the ice is not yet that thick, make it melt by pouring the hot water over the ice. The ice will then melt again quickly.
In any case, keep the iced area free of snow so that enough light can reach the plants and fish.
It would help if you kept your garden pond free of ice in the winter so that the fish and plants are sufficiently supplied with oxygen. Shallower ponds have the most significant risk of freezing over. Evergreen pond plants serve as natural ice keepers. However, they are not always sufficient. Besides, you can use ice-freeholders, which are equipped with sink chambers. You can integrate a heater into the ice-freeholder. Pond heaters, heating cables, and frost-free pumps are also efficient and reliable. If the ice does freeze over, place a pot of hot water on the ice area. It would help if you always cleared the frozen area of snow so that the plants and fish get enough light.