Pumps and filters
You won’t need
to filter the water but it’s a good idea to keep it moving at
the pond’s surface.
Pond life needs
oxygen even during hibernation. If ice covers the surface of the pond,
oxygen can’t get in and toxic gasses can’t get out.
with fountains or waterfalls will oxygenate the water and keep a
portion of the pond from freezing. If you live in an area that freezes
solid I recommend using a pump and fountain to aerate the water.
Set the pump on
bricks about one foot below the water. This will prevent the pump from
getting clogged with leaves.
If your fountain
output appears to be diminishing, check the pump to make sure it is
not clogged. Floating pond heaters are available to keep a small area
free of ice.
You can also use
an aquarium air pump and diffuser stone to oxygenate and prevent ice
formation. Even if the pond completely freezes over, the air pump
keeps pumping oxygen into the water.