Your pond is likely to freeze over during any prolonged cold weather we experience during the winter. This leads to many of our garden centre customers wondering whether the presence of ice is a danger to their fish. Snow will also cut off light, preventing plants from producing oxygen. And don't forget, if you make sure that a portion of the pond is ice free, it is not only plant life and amphibians who will benefit, as birds will be able to drink and wash their feathers in the unfrozen water.

Pond Heaters

Pond heaters are very effective at keeping at least part of the pond surface ice free. These are relatively simple devices with heating elements, they are cheap to run and very effective.

Oase Ice Free Thermo Pond Heaters are effective even in temperatures as low as -20°C. A thermostat ensures that the heater isn't wasting energy when the temperature is above freezing, and both 200 and 330 watt models come with 10 metres of cable.

Cloverleaf Pond Heater

Cloverleaf pond heaters are made from high quality stainless steel with a very efficient titanium element. There are 1kw and 2kw versions suitable for ponds up to 9000 litres / 2000 gallons. The hosetail allows you to connect the heater to a filter and they are temperature controlled.

The Velda 300 watt Pond Heater is made from stainless titanium and can also be used with a compatible filter for crystal clear as well as ice free water. A 50 watt Blagdon Affinity Ice Vent Pond Heater will operate in temperatures as low as -10°C and can be used for ponds of up to 5000 litres / 1100 gallons at a maximum depth of 1.2 metres and comes with a 10 metre cable.

Aeraters / Pumps

Aeraters and air pumps are an alternative to heaters and can be cheaper to run. By diffusing oxygen and circulating water, in the winter they keep the pond ice free and during the summer will aerate the water, increasing oxygen levels when your fish are most active.

Oase AquaOxy

There are two Oase AquaOxy models, with 1000 and 2000 litres per hour air displacement. They both work off low voltage and are therefore cheap to operate in ponds of up to 20,000 litres / 4444 gallons.

The same company's OxyTex aerater/filters are multi-functional, supplying oxygen, increasing circulation and, by accommodating bio-organisms over a large surface area, encouraging nutrient decomposition. The OxyTex is available individually as well as in a Oase Oxy Tex Set set that includes a pump.

There's also the Oase Ice Free Four Seasons which has a double identity, in the summer it's a fountain and in colder weather it functions as an ice breaker

Designed for ponds up to 2250 litres / 500 gallons, the Blagdon Pond Air 1 has a 4 watt pump giving an air flow rate of 210 litres per hour. The more powerful Air Pump 2 is designed for 4500 litre / 1000 gallon ponds and comes with two 50mm air stones and 8 metre lengths of air line, consuming only 5 watts, it has a maximum flow of 330 litres per hour.

Koi Air

Blagdon also produce powerful Koi Air Pumps for water to a depth of 3.5 metres with 8, 12 and 18 air stones and maximum flow of 65 litres per minute Pontec PondoAir pond aeration sets with two air stones are available in three versions with capacities of 200, 450 and 900 litres per hour.

Hozelock's Ice Preventer floats on the surface with the air stones suspended in the water, it uses a 320 or 640 litres per hour pump that is sold separately. The V-Tech Air Power Air Pump Set also has two air stones and has an electronic output control while there are five versions of EvolutionAqua with a maximum operating depth of 5.5 metres and a flow rate of 70 - 150 litres per minute. Finally, the Pond Heater Alternative comes with an 8 metre airline and 50mm air stone and is suitable for 2275 / 500 gallon ponds.

For further information and advice, visit Ice Prevention on GardenSite, contact our Aquatics Department on 0121 355 7701, email: [email protected] or visit our Aquatics Superstore in north Birmingham which is open seven days a week.