NEWS113
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(Nymphaea), and Aponogeton as the
main components of the planting. This
typeof substrate isusedasabottom layer
in the planted zone of the aquarium, i.e.
beneath the gravel in the example
describedabove.
Clay
Clay is composed of very fine-grained
minerals with a grain size of between 1
and4µm (1µm=0.001mm).Theeffectas
aplant fertilizer isn'tproperlyunderstood.
It is thought, as mentioned earlier, that it
actsasacatalystandenables theplants to
take up certain substances, while
simultaneously
binding
poisonous
substances. For this reason clay is also
used inhumanmedicine. It is thought that
on the one hand the huge surface area
has a high binding capacity and on the
other the substances thus bound up are
also subsequently released again.Various
manufacturers
offer
clay
pellets
containing slow-release fertilizer. These
pellets are simply pressed into the
substrate close to the plant to be
fertilized.
The effect of this root fertilization is
usuallyquiteastonishing,Manypreviously
sicklyplants literally explode intogrowth.
Further fertilization isn't requireduntil the
effect diminishes. Preciselywhen thatwill
becan'tbeprophesied,aseveryaquarium
functions in its own individual way, but
usually this type of fertilization remains
effective for severalmonths.
Peat
Fundamentally the use of peat, especially
granulated peat, in the substrate isn't
advised. It usually only leads to a
dreadfully stinking substrate with dying
plants. However peat can, when targeted
at the root region of a plant, have a very
positive effect. This is because almost all
aquatic plants require a very narrow pH
range for optimal growth, specifically
between pH 6.2 and 7.0. Peat - or at least
some types of peat - has the effect of
lowering the pH. So peat can be used to
help incaseswhere thepH is toohigh.The
most suitable type is pellets of
compressed peat as offered by various
manufacturers - e.g.Aquariana - as a filter
medium for pH stabilization. The pellets
are simplypressed into the substratenear
to the plant, as described earlier for clay
pellets.
Compost
The effect of compost on plant growth is
phenomenal. Unfortunately, as already
mentioned, normal compost cannot be
used in the aquarium because the
resulting bacterial proliferation will lead
tocloudywater andaplagueof algae.But
youcanandshoulduse ”light compost”in
the form of dead autumn leaves. Dead
leaves
are
an
indispensable
supplementary food for almost all aquaria
and will also supply the fishes and other
aquarium occupants with important
secondary plant substances.Addone leaf
per 10 liters of tank volume to the
aquarium, and repeat when it has
"disappeared". As then it will have been
composted and vanished into the gravel,
where it will serve the living plants as a
perfect,natural nutrient supply.
The roots of the aquatic Banana Plant,
Nymphoides aquatica
, are used to store
nutrients and shouldn't be buried in the
substrate.
Satanoperca rhynchitis
in the aquarium. In this instance the red lips are not the result of inflammation
causedby thewrong type of sand,but a characteristic of the species.The siftingof sand is a necessity
for all Satanoperca species.The sifted sand isexpelledvia thegill-slits and trickles to thebottom,as can
clearlybe seen in thephoto.
