_
'
.
WaïteiElters
_
"83
' _
Container; Ideal—ly the filter plate «should cover the whole basé area
and shouldnot allow Water to flow pastits edges and…bypasS the bed.
It should have an efficient air—lift mechanism which will circulate
water evenly Over the whole bed‘area and the plate perforations —
Should be such that gravel, mulm and so on are not drawn through to
’
lie beneath the filter plate and thus impede circulation. The plate
_
must be rigidly constructed so as to take the weight of the gravel
bed and any other heavy material above, such as decorative rocks,
without sagging, and the junction between the air-lift mechanism
,_
and the filter plate must be sound. For added efciency, the air—lift
tube should preferably include space for the inclusion of a diffuser
stone.
"
available to the home constructor are corrugated plastic ]
sheeting, used normally for roofing; and small bore plastic piping in
various sizes as used in domestic water systems. Both must be made
*
in non-toxic materials and plastics should be tested before use, espec—
ially when they are
to be used in marine environments. All cuts, holes
,
and slots should be made smooth to eliminate small particles Which
i
could harm fishes, and perforations in corrugatçd sheet should be in
‘
the troughs of the corrugations. Non—toxic joints can be made with
silicone rubber sealant but tests should be made to see that it adheres
_
properly to the particular material used.
.
_
Ÿ
To achieve the most even circulation of water through the _whole' ,Ÿw
bed area it isbest. if the air-lift is situated in the
of a
_
plate; but as aqüaria are usuallyanything but circular and &
air lift is not very convenient there is‘ineVitably Some loss
formahCe’forthis reason. However, this loss Can
madeverysmall
if
other important points are
to
and enough a1r1s
provided. »_
&
‘
'
;
-
.
‘
“The main physical 'advantage‘of‘ the‘sub—gr‘avel filter. overother
'
types“ is that it is hidden inside the environment
and
‘tract‘fro‘m the Overall “appearance. of the aquarium.“ Comparedw1th
—mounted filters italloWsrows‘”of aquatiatobef1ttedup
:
figlÏ-tlÿside by side“ for economy of space—. Its main disadvantagesare
f that it is» not easily acCessible should “anythinggo wrongandltsuse
demands aîgdeep
“bedthich @@ spoil thelookofadecoratwe
aquarium unless
gravél showing ab Ove thé-b ott0r=frameofthe
' _
container is Camouflang in
:—
…
(F1gure 30) is“ shown—"f mF1guf€31Areverseflowacüoncausesau
'
.
WaïteiElters
_
"83
' _
Container; Ideal—ly the filter plate «should cover the whole basé area
and shouldnot allow Water to flow pastits edges and…bypasS the bed.
It should have an efficient air—lift mechanism which will circulate
water evenly Over the whole bed‘area and the plate perforations —
Should be such that gravel, mulm and so on are not drawn through to
’
lie beneath the filter plate and thus impede circulation. The plate
_
must be rigidly constructed so as to take the weight of the gravel
bed and any other heavy material above, such as decorative rocks,
without sagging, and the junction between the air-lift mechanism
,_
and the filter plate must be sound. For added efciency, the air—lift
tube should preferably include space for the inclusion of a diffuser
stone.
"
available to the home constructor are corrugated plastic ]
sheeting, used normally for roofing; and small bore plastic piping in
various sizes as used in domestic water systems. Both must be made
*
in non-toxic materials and plastics should be tested before use, espec—
ially when they are
to be used in marine environments. All cuts, holes
,
and slots should be made smooth to eliminate small particles Which
i
could harm fishes, and perforations in corrugatçd sheet should be in
‘
the troughs of the corrugations. Non—toxic joints can be made with
silicone rubber sealant but tests should be made to see that it adheres
_
properly to the particular material used.
.
_
Ÿ
To achieve the most even circulation of water through the _whole' ,Ÿw
bed area it isbest. if the air-lift is situated in the
of a
_
plate; but as aqüaria are usuallyanything but circular and &
air lift is not very convenient there is‘ineVitably Some loss
formahCe’forthis reason. However, this loss Can
madeverysmall
if
other important points are
to
and enough a1r1s
provided. »_
&
‘
'
;
-
.
‘
“The main physical 'advantage‘of‘ the‘sub—gr‘avel filter. overother
'
types“ is that it is hidden inside the environment
and
‘tract‘fro‘m the Overall “appearance. of the aquarium.“ Comparedw1th
—mounted filters italloWsrows‘”of aquatiatobef1ttedup
:
figlÏ-tlÿside by side“ for economy of space—. Its main disadvantagesare
f that it is» not easily acCessible should “anythinggo wrongandltsuse
demands aîgdeep
“bedthich @@ spoil thelookofadecoratwe
aquarium unless
gravél showing ab Ove thé-b ott0r=frameofthe
' _
container is Camouflang in
:—
…
(F1gure 30) is“ shown—"f mF1guf€31Areverseflowacüoncausesau