With the amount of rain we’ve had in the latter part of 2012, combined with the constantly dropping temperatures, it was inevitable that we would eventually get snow and the dreaded frost! For those of you with ponds (especially those of you with fish ponds), you may be wondering what on Earth you can do if your pond freezes.
Let’s start with what you shouldn’t do. Do not turn off your pump or filter, the running water may well be the only thing that’s actually stopping the whole unit from freezing and becoming damaged. If the water’s flowing, let it flow, let is flow, let it flow!
So, what can you do to stop your pond from freezing completely. You certainly don’t need to worry too much about some ice on your pond, with this weather and at this time of year, it’s practically unavoidable; but what you won’t want, is for it to freeze completely over.
Even underneath a closed sheet of ice, the garden pond stays biologically active. Decaying vegetation and other organic compounds decompose and release toxic gases such as hydrogen sulphate in the process. If the pond is completely frozen over theses toxic gases cannot escape. Fish and other aquatic life forms which live in the lower and warmer parts of the pond during the winter cannot deal with this situation. Quite often fish die of toxic poisoning due to paralysed respiratory tracts. Furthermore, the closed sheet of ice eliminates contact with the atmosphere, hence the oxygen content of the water can sink dangerously low and in turn can also cause your fish to die.
The best way to prevent your pond from freezing over entirely is to use an electric pond heater. This will keep an area around the device free from freezing over and allow the gas exchange necessary to maintain your fish. There are a couple of different options when it comes to pond heaters. First you have the Aqua El 300w Pond Heater. This heater is a floating pond heater which provides spot heating of the pond water surface in the winter and maintains an artificial blowhole when the surrounding temperature falls below 0 deg C. The hole maintained by this heater allows essential gas exchange in the pond, therefore protecting your fish from the suffocation mentioned above. An alternative heater is the Oase IceFree Thermo 200. This basically does the same job as the Aqua El 300w Pond Heater but has a slightly lower power consumption at 200w rather than 300w, and is safe to use for temperatures down to -20°C. Due to the lower power consumption it will also be slightly less powerful than the Aqua El. The premium model when it comes to pond heaters is the Oase IceFree Thermo 330 . This is the model up from the Oase IceFree Thermo 200 and is the most powerful pond heater of the three, with a power consumption of 330w. The main advantage of the Oase IceFree Thermo 330 over the other two, is the fact that it comes with an integrated frost monitor With this energy saving function the device is only activated when there is actual danger of frost. So although it actually uses more power than the other two, it will actually use less power overall due to the automatic on/off function.
Ice Preventer’s use a float connected to a small pump. The pump is hung in the pond and transports small amounts of water from the warmer layers in the lower parts of the pond to the float. The constant supply of water with a temperature of 2-4 degrees C keeps the pond surface to a diameter of approx. 20 cm around the float, free of ice. There are a couple of different varieties of this device, but in our experience none as good as the Oase IceFree 20. The Oase IceFree 20 ensures reliable performance in temperatures of up to –20° C and requires only a very small flow rate so that the power consumption is kept amazingly low.
You can dose your pond with salt. This will help reduce the temperate at which the water freezes making it difficult for it to completely freeze. The dose rate is 0.5 ounce per gallon of water; use the table below to calculate the dosage for your pond.
Dosing ponds with salt, while safe for fish, is not suitable for plants; so do bare this in mind when considering this option. It is also important to monitor salt levels so that the level does not exceed 0.5 ounce for gallon of water. Salt is available in-store at Paddock Farm with prices ranging from £5.60 right up to £17.00 for 25kg. Unfortunately due to the weight of the salt we are unable to ship it, but you should be able to get some in your local garden centre/supermarket.
Why can’t I just move my fish indoors?
There’s a considerable amount of stress involved in catching and moving pond fish, so there really needs be a ‘no other option’ scenario to make this viable. In addition the temperature difference between your outside pond and your house is considerable, rapid changes in temperature can be very stressful to fish and you’d have to keep them indoors until the temperature found balance with the ambient temperature around your house (in other words, you’d have to keep them indoors until at least March); so we would really not encourage this an an option.
If you have a tried and tested method that we haven’t mentioned, let us know below!