If you live in the Northern part of the US you can bet that Mother Nature will once again show us her cold shoulder this winter. If you live in the northern most tier of states like Michigan, Minnesota, Wisconsin, etc. then you can expect a long spell of freezing weather which will cause excessive ice on your pond. In a small body of water this ice formation can be deadly to the fish because it not only blocks out sunlight from getting into the pond but it also prevents gases from escaping. There are three main ways to keep your fish happy and healthy all throughout the winter months.
Bubblers
An air bubbler is generally the best choice for ponds and pocketbooks for the majority of watergardeners because it’s more economical to operate. Bubblers are also more reliable than deicers and heaters and can reduce any need to fix the pond in the middle of a frigid winter season. Typically, these systems have an onshore air compressor which pumps air through a tube and then out to an air diffuser at the bottom of the pond. They are available in many sizes and styles for use in small water gardens up to large earthen ponds. The bubbling is caused by the air stirring the water, which creates and maintains the opening. In cases of extreme cold, honeycomb-shaped ice will form on the pond. Unlike thick ice, this uniquely-shaped layer of ice will allow gases to escape even though the pond appears to be frozen over. The compressor for the bubbler is located onshore, which makes servicing it a snap. Bubblers are far more energy efficient than their high wattage counterparts and can be used year round because the bubbler increases the oxygen levels, improving water quality in the summer.
Deicers
Deicers are small, floating heaters that float on the pond’s surface. Most have an internal 100-300 watt heating element that provides just enough heat to keep a small portion of the surface thawed. The small hole in the middle of the donut-shaped unit may be the only part of the surface that stays thawed but it is enough to allow toxic gases to escape and to keep the fish safe. One major draw back to deicers is their electric usage. At 100-300 watts of power (some are as much as 1200 watts!) deicers use more electric than air bubblers and if a failure occurs during the winter the units freeze in quickly and usually have to be chopped out of the ice.
Heaters
Heaters are similar to deicers in that they use electricity to create heat. Unlike deicers, heaters are primarily used by those watergardeners who house their fish indoors for the winter. For example, a heater is used for fish stored in a basement or garage in order to bring the water temperature up into the mid-60s or 70s. The heating element sits on the bottom of a tank and raises the water temperature to prevent the fish’s metabolism from slowing too much. Choosing to put a heater outdoors in the pond can prove to be costly. Not only will the unit likely run continuously, using lots of electricity, but the fish will never get a chance to hibernate. Cold water will slow your fishes metabolism down tremendously, using a heater outdoors can keep their metabolism in limbo which can cause significant weight loss and poor health.
All three pieces of equipment will work well when used correctly and in the right circumstance. By determining your needs you can select which product is right for you and keep your fish happy until the last snowflake falls.