26
‘
The AquaticEnüibnmen:
-
-
:
“
bacteria depends on the quantity of waste available,
nitrifying'bacteria cannot develop inlarge quantities unless sufficient
_
inorganic material of a suitable type (e.g. rocks, glass, gravel) xis
present. Thus, if
does not include enoughof this material,
or
som—e substitute for it, the nitrogen cycle will only be partially
completed and the only protection against increasing toxi'city in the
aquarium« will be scrupulous cleanliness and the exclusion of all
_…Ï
wastes. This is a lengthy and tedious process which can usually be
»“
avoided by carefül management.
Table 3. PROGRESS OF THE AQUATIC NÏTROGEN CYCLE AND THE
_
RELATIONSHIPSOF VARIOUS CLEANlNÇ_METHODS AND THEÏR
’
POINTS OF APPLICATION (Court
_
The Aquarist and Pondkeeper () .
Proce$s
Rêsulting
Relevant
Mode of Operation
products
methods
_
'
Accumulation of Organic waste as Siphoning and
Removes accessible
‘
uneaten food,
visible detritus
manual removal
pieCes physically
_
dead animals,
and also dis__
excreta and
_
organic
Mechanical filtra—
,
Continuod‘sly removes
Ï
urine, plant
Chemicals
tion with nylon
small pieces and reduces
.
“
material
_
wool or diatomaturbidity._DE can filter
‘
‘
ceous earth (DE)
particles doWn to 1
_
“
*
,
_
'
micromètre and remove
bacteria and protozoans
’
-
Absorption by
Removes dissolved
_
'
activated carbon
…
_
_
.
»
_
«
/
'
Minerasation
Ammoniacal
.
Water changing,
Dilutes concentrations
_
of organic waste compounds.
either completely
of toxic substances.
'
_
'
'
by heterotroTypical toxic
or partially
“=
bacteria
level 0.5 mg/
‘
litre
'
lon—exchangeresin
Absorbs ammonia and Ï
'
“
.
—
nitrate. Not suitable for
-
'
'—
*
'
salt wat—er
,
-
,
_
bubblë commns and prolongedoontaetw1th
"
‘
…
_Î numerousalrsurfaces '
.
À
‘
duemremovableform
f…:—.
.
«'…
-’
:
in_
ammonia by —.