Keep and eye on your stream, as this is a likely spot for
problems with ice. An ice dam can be created and actually pump
water outside the pond.
De-icers or pond heaters are ideal devices to guarantee that
you do not suffer from an ice-over. The heater is not designed
to heat the entire pond, but just to allow a portion of the pond
to remain in contact with the air. This will allow the gases
to transfer from the pond to the air. An open area in the ice
can also be maintained by leaving your waterfall pump, bubbler
or air pump running during the winter. Place any of these devices
in the upper one third of the pond. You want to leave the deeper
part of the pond undisturbed.
If by chance Mother Nature moves faster than you and you suffer
an ice-over before you've obtained a de-icer or air pump you
should not break the ice with hammer or shovel. The fish will
not like it much, just as you see the signs at the aquarium store
saying do not tap on the glass. To remedy your oversight until
you can install the de-icer, you can take a pan of boiling water
and set it on the ice to melt a hole. This may take multiple
trips. You can also use a drill and open up several holes. These
methods are tricks just to make it through in a pinch. I would
not plan on this way to ice-over prevention because it will be
very cold drilling a hole in the pond twice a day or carrying
boiling pans of water out of the house when it's 5 below zero.
With proper preparation you can sit back with a mug of hot
cocoa and enjoy the natural sculpture that a waterfall creates
during the winter months. Pond keepers know that the best season
is the current season no matter what season it is.