related article: Garden Pond Cleaning | Pond Vacuum Cleaner
You will need a thermostatically controlled pond heater and floating de-icer for your Koi pond in winter to keep temperatures constantly above 25°F and to provide an ice-free area by preventing the surface of your garden pond from freezing over completely.
Specialized dealers offer an pond de-icer and ice chaser, that prevents your water garden from icing over even at minus 4°F for less than $100.-.
Starting at similar prices (less than $100.-) they offer modern thermostatically controlled pond heaters, that switch on automatically as soon as pond temperatures drop below 25°F. Such garden pond heaters and ice chasers guarantee stabile living conditions for your Koi fish and other sensitive species of goldfish throughout any cold winter.
It is important that Koi have at least a pond depth of more than 36". Your Koi will hibernate at the bottom of your garden pond where the warmer thermal layers are.
Pond heaters already operate efficient in a regular Koi pond in winter with just 100 watts. Big ones are available up to 2kw and 3kw.
Never try to break the ice of your water garden. Beating on the ice causes sound waves underwater that will damage the swim bellows of your fish. So in spring they won't be able to swim as usual and they will die. If you haven't installed anything to keep an area free of ice, you can melt a hole into the ice by pouring hot water very slowly through a piece of PVC waste pipe. This method will produce a first hole in the ice for gas and oxygen exchange. But now you should install a floating or submerged de-icer unit.
The natural way to provide gas exchange is by cutting your reed plants above water level so in winter they keep natural holes in the ice.
Also bundles of straw will help as a natural prevention against an airtight sealed pond. Other methods try to keep an ice-free area with plastic balls moving on the water surface or with air pumps. These methods may be enough for a natural plant pond, but as soon as you have fish that hibernate in your water garden you need to install winter-proof pond equipment. Floating or submerged pond de-icer, thermostatically controlled pond heaters and winter-proof air pumps really provide adequate oxygen and prevent fish and plants from freezing.
A modern and low-price de-icer use only 100 watts, what is less than 1/10 the electricity of a conventional pond de-icer. For small garden and fishponds the right choice.
Besides conventional air pumps there are modern and more efficient oxidizers, that produce oxygen by a chemical reaction. Once refilled in autumn these units provide your fishpond with enough oxygen through a cold winter season.
Some garden pond owners cover the whole water surface with PE balls to keep it ice-free. These balls help to keep warmth inside the pond by closing about 90% of the surface and by getting heated up by daily sunshine. These pond balls may save up to 80% of your pond heating costs and are faster installed than any complete covering roof construction above your pond. After the winter season these pond balls need to be stored, what may take up quite a lot of space.
An oxidizer should be serviced before winter. No pond water should seep in and no fluid should drop out into the pond. If necessary, you should clean the oxidizer with special oxidizer fluid when winterizing your garden pond. Following these and other vital fishkeeping tips, including a efficient pond maintenance before winter will help your pond life to hibernate healthy and without any harm.