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Looking after your wildlife pond
Nearly everything
that goes on in
your wildlife pond
relates to the
nutrients in the
water.
20
Wendy Sabine
Pond nutrients and
blooming problems
Nutrients are plant food. They exist in the
soils, float freely in the water and they are
released when dead plants, leaves and animals
decompose.
The presence of free nutrients in the water
can lead to so-called ‘algal blooms’. Being
small and quick to reproduce, the algae (or
phytoplankton) can replicate exponentially
causing a murkiness or algal cloud (sometimes
quite thick) to form in the water. Often
what’s lacking in these situations is an animal
predator - a classic is the water flea (
Daphnia
),
a species capable of reducing phytoplankton in
a matter of days.
If your pond lacks water fleas then (with
permission) consider asking a nearby garden
pond owner for a small amount of silt and
water, but be careful about transferring plants
with it (see page 12).
Daphnia
can also be
purchased.
Alternatively, to treat the immediate problem
try barley straw or barley straw extract.
Both duckweed and blanket weed are
indicators that the pond has a lot of free
nutrients in the water. To tackle this consider
adding larger pond plants - their growth will
use up some of the free nutrients in the water
and hinder growth of problem plants. If this
doesn’t work it might be worth considering
cleaning the pond out the following autumn.