Page 322 - Encyclopedia of Aquarium and Pond Fish, 3rd Edition

320 POND FISH: MAINTENANCE

part of the pond, where pond fish spend the winter. If there
is a submersible pump installed, position it more than 6 in
(15 cm) from the bottom of the pond, and switch off water
features, such as waterfalls or fountains—otherwise, these will
circulate and cool the water by mixing the colder surface
layers with the warm layer below.
In mild areas, a pond heater can help to prevent the surface
of the pond from freezing over in the winter. It will stop the
area around the heater from freezing, allowing noxious gases
produced by decomposing plant matter to escape from under
the ice. If ice has formed on the surface of the pond, never try
to smash it, because the shock waves will traumatize the fish
and may even prove fatal. Instead, melt the ice slowly by
carefully holding a hot saucepan on the surface of the pond.

During the spring, place a net over the surface of the pond or
stretch it across a framework to protect exhausted fish from
opportunistic predators. Decoys are available to deter birds, but
they are unlikely to stop raccoons or cats.

CLEANING OUT A POND

Over time, sediment accumulates in the pond, and plant growth
proliferates, inevitably reducing the area of water that is accessible
to the fish. At intervals of a year or so, it is a good idea to unertake
a major clearout. The best time is in early spring, because the pond
will have time to reestablish itself in the warm summer months.
If any cases of serious illness have occurred within the pond, it may
require disinfection. Some preformed pond units can be lifted out
of the ground to make this task easier.
• Before starting the clearout, catch the fish and move them to
a location where they will be safe.
• Siphon or bail out the pond water, removing other aquatic life,
such as snails or dragonfly larvae.
• Divide and repot water lilies and marginal plants.
• Remove the silt using a spade or scoop, and hose out the base
of the pond. The used silt can be dumped on flowerbeds.
• Refill the pond, adding a suitable volume of water conditioner.
• Allow the water temperature to rise before returning the fish and
plants to the pond.

The surface of a pond can become choked with aquatic vegetation (top). Clearing
Remove the fish before cleaning, Reintroduce the fish only after any out the pond, by thinning or cutting back the plants and removing dead matter,
watching closely for small fry; replanting is complete; allow the fish provides the fish with a larger swimming space and makes the area neater,
transfer the fish to a safe container. to settle without further disturbance. safer, and more attractive (bottom).

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