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43
The ”system is also artificial both aesthetiCallyand bi010gi‘callÿàñd *
«
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‘
by its very nature
must be maintained ina spotlessly‘ clean
,
The aquarist is advised to consider very carefullyhis own require-f
’
ments and other available methods before becoming
system of this kind. In particular, it should be noted that the
ment
of successful biologicalsystems has made sterile methods
sor‘newhat redùndant.,
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f
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As with the first two systems described, the basic problem is to
,
achieve successful completion of the nitrogen cycle. The equipment
which performs this function in this system usually comprises a
large mechanical filter, an ozoniser, and a protein skimmer (see
Figure ”10), In addition, an ultraviolet steriliser may be used to
prevent disease. All of this equipment is expensive to install and
—
maintain and the aquarist is totally dependent on it functioning
correctly. Feeding is carried out sparingly and carefully with artificial
foods and nothing is put into the aquarium which has a remote chance
of causing pollution or disease. The main reasons for taking all this
…
trouble are simply to minimise the risk of losing expensive specimens
in
imperfect natural environments and also to provide a
method which, given the availability of meeizalised
cam
be set
smc…
creviu
ment, other than
;Llltl
…c
…Leii‘…r
cqdipnrcnt, arc
either ornamental or perform a psychological function for the fish,
such as providing hiding places. These corals, rocks Or Whatever,àfeÂ
previously
bothvchemically and biolo‘gically_,and;…
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this process is
the life
virônment. - At Such times a large proportion of the water
lac—changed to ensure dilution *of‘any toxic compôunds whichmay
..
not
been removed by the purifying-«equipment; N o
are inéluded‘ as these would hold dirt andmake
mor—e
:
,
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-
One
the
for ageing water before instàlling‘ the
systems is to
the start.‘_In’a a sterile systemany_
baCtea,plankton and [so
,
on,? whether—; harmfuls or benef1c1a1,areî
’
v‘æjlÏëS@@kledbythequipmcntand SO 'thère
maturedWter f®rîh18purpose On the » 0 the—F
. Prcessmaÿremveunwanted constituent—s su0has chl@lme ‘ï'êàid‘ï
forthlsreasnmaybenecessary
_