JPH025125B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a filtration device, particularly a flat suction section that is installed at the bottom of an aquarium so as to be buried in gravel spread in the aquarium and has a water absorption hole in the upper wall, and a purification section connected to the suction section and housing a filter body therein for filtering water introduced into the aquarium through the suction section; The present invention relates to a filtration device having a water absorbing means, which performs a filtration action not only on the filter body but also on a gravel layer above the suction section.

This type of filtration device is conventionally known as a so-called bottom type filtration device (see, for example, Japanese Utility Model Application Publication No. 51-80499), and in this type of device, filtration is performed primarily in a gravel layer spread at the bottom of the aquarium. It has a unique advantage that so-called top-type filtration devices do not have, such as the ability to effectively use organic matter such as leftover food and feces of ornamental fish as nutrients for aquatic plants planted in the gravel layer.

By the way, in the above-mentioned bottom type filtration device, if the water absorption rate in the gravel layer or filter body is too slow and water stagnates, the reproduction of anaerobic microorganisms in the gravel layer or filter body will be promoted and the ornamental fish in the aquarium will be destroyed. On the other hand, if the water absorption rate is too fast, the growth of aerobic microorganisms in the gravel layer and filter will be inhibited, making it difficult for aerobic microorganisms to decompose organic matter. However, especially with conventional devices, all of the water sucked into the suction unit through the gravel layer always passes through the filtration surface of the filter before being sucked into the water absorption means, so there is a risk of clogging of the filtration surface. The water absorption rate changes greatly depending on the degree of water absorption, and especially when the filtration surface is completely clogged, the water absorption effect of the suction part and the primary filtration effect of the gravel layer will be extremely insufficient. There is a problem of rapid deterioration of water quality.

The present invention can solve the above problems.
The purpose is to provide a filtration device with a simple structure. In order to achieve this objective, according to the present invention, a flat plate is installed at the bottom of the aquarium so as to be buried in the gravel spread in the aquarium, and for introducing water into the aquarium through the gravel. a suction part; and a suction part that extends along the entire length of one side edge of the suction part, stands above the suction part, and is provided inside to filter water introduced into the aquarium through the suction part. A purification section that accommodates a filter body, and a water absorption means for circulating the water filtered in this purification section back into the aquarium, so that the gravel layer above the suction section performs a filtration action. In the filtration device, the upper wall of the suction section is composed of a high section extending along and adjacent to the purification section, and a low section connected to the high section via a stepped section, and Directly below the plurality of flow passages, and immediately below the high part, there is provided a gathering chamber that communicates with one end of the plurality of flow passages, and the lower part has a plurality of flow passages and the inside of the water tank. A plurality of water suction holes are drilled to communicate with each other, and the filter body has a plurality of water suction holes in the purification section, an unpurified chamber in which the collecting chamber opens over substantially the entire length thereof, and a purification chamber in communication with the water suction means. a filtration material for filtering a portion of the water heading from the unpurified chamber toward the purification chamber; and a filtration material for guiding the remainder of the water to the purification chamber by bypassing the filtration material. It has a small hole for

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. First, in FIGS. 1, 2, and 3, gravel 2 is spread in an aquarium 1, and the filtration device 3 of the present invention has at least A portion is buried in gravel 2 and installed at the bottom 1a of the aquarium 1. With the filtration device 3 installed in the aquarium 1 in this way, by operating the water absorption means 4, the water in the aquarium 1 passes through the gravel 2 and passes through the filtration device 3.
Furthermore, the filter body F ₁ in the filter device 3,
After being filtered with _F2 , it is refluxed to the upper part of the water tank 1.

The casing 7 of the filtration device 3 has a flat box-shaped suction section 8 with an open bottom and openings 9a, 9a at the top.
A rectangular cylindrical purifying portion 9 which is closed by a pair of lids 10 and 11 and extends vertically is integrally connected, and is integrally molded, for example, from synthetic resin. The suction section 8 includes an upper wall 12 and a U-shaped side wall 13 that is open on the purification section 9 side. The purification section 9 is
Consisting of a pair of side walls 14, 15 facing each other, and a pair of end walls 16, 17 facing each other by connecting the ends of the side walls 14, 15, the suction is inserted into a connecting port 50 at the bottom of the side wall 14. Parts 8 are joined at right angles. Therefore, the casing 7 is formed so that its longitudinal cross-sectional shape as a whole is approximately L-shaped.
Moreover, the suction section 8 is formed to be relatively long both in the direction perpendicular to the side wall 14 of the purification section 9 and in the direction extending horizontally along the side wall 14, and is
It is buried over a relatively wide area.

The upper wall 12 of the suction part 8 has a lower part 18 and a higher part 1.
9 are connected to each other via a stepped portion 20, and one side edge of the high portion 19 is connected to the lower part of the side wall 14 of the purifying portion 9. The low part 18 extends relatively long along the bottom 1a of the water tank 1, and on the lower surface of the low part 18, a plurality of partition walls 21 extending in a direction perpendicular to the side wall 14 of the purification part 9 are mutually connected. Hanging parallel to each other at intervals. For this reason, the casing 7 is placed in the water tank 1.
When placed on the bottom part 1a of the
8. A plurality of mutually parallel flow paths 22 are defined by each partition 21, the bottom 1a of the water tank 1, and the side wall 13 of the suction part 8.

In the upper wall 12 of the suction part 8, a plurality of water suction holes 23 are bored in the lower part 18 at intervals along the longitudinal direction of the flow passages 22, which communicate the flow passages 22 with the inside of the water tank 1. Ru. Moreover, each water absorption hole 23
The mutual spacing is set to become smaller as the distance from the purification section 9 increases. In the upper wall 12, water absorption holes 23 are formed in the high portion 19 and the stepped portion 20, respectively, on an extension of the flow path 22, and the side wall 13 of the suction portion 8 also has a plurality of water absorption holes spaced apart from each other. 24 is drilled.

The pair of upper openings 9a, 9a of the purifying section 9 are formed in a size that allows the filter bodies F1 _{, F2} to be inserted into and removed from the purifying section 9, respectively, and in use, the pair of lids 10, 11 respectively. Thereby, when the casing 7 is placed on the bottom 1a of the aquarium 1, a filtration chamber 25 is defined within the purification section 9. The lower part of this filtration chamber 25 is a gathering chamber 26 defined directly below the high portion 19 of the suction section 8.
It is commonly communicated with one end of each of the flow passages 22 through.

In the filtration chamber 25 of the purification section 9, the filter F ₁ ,
F ₂ is accommodated. The filter media 5 and 6 of each of the filter bodies F ₁ and F ₂ are bent in a waveform in a horizontal plane, and are inserted into the frames 27 and 28 respectively so that the shape is maintained, and are placed in the filter chamber 25. are connected to each other endlessly via a connector 29. Therefore, the inside of the filtration chamber 25 is a purification chamber 30 inside the filter media 5 and 6.
and an unpurified chamber 31 which is located outside the filter media 5 and 6 and is open over substantially the entire length of the gathering chamber 26.

The pair of lids 10, 11, filter media 5.6, and frames 27, 28 have exactly the same shape and configuration, and the filter media 5, 6 held by the frames 27, 28
are supported by the lids 10 and 11 via the frames 27 and 28, respectively, and are arranged symmetrically within the filtration chamber 25. This reduces the size of filtration device 3 by 1/2.
When the size of the filtration device 3 is reduced to 1/2, it is sufficient to use a combination of one lid, one frame, and one filter material. Hereinafter, only the configurations of one lid 10, the filter material 5, and the frame 27 will be described.

Referring also to FIGS. 4 to 6, the lid 10 is
A pair of side plates 32 and 33 that face each other with an interval larger than the distance between both side walls 14 and 15 of the purification unit 9 and a space between the side plates 32 and 33 so as to fit into the upper end of the purification unit 9 are provided. The top plate 34 is connected to the top plate 34 and has a substantially U-shaped cross section. In this lid 10, a support tube 35 that communicates with the inside of the purification chamber 30 is suspended from one end of the top plate 34, and the support tube 35 expands and exerts an elastic force directed inward in the radial direction. In order to achieve this effect, a plurality of slits 36 extending vertically are bored at intervals in the circumferential direction.
Further, a plurality of engaging claws 38 extending downward are provided on the side edges of the top plate 34 in a protruding manner. Furthermore, each side plate 32, 33
Water holes 39 extending vertically are formed at intervals in the.

The frame body 27 includes an upper support plate 40 and a lower support plate 4.
1 and a plurality of connecting rods 42 that connect both support plates 40, 41. The upper support plate 40 is formed in a rectangular shape with a width that allows it to fit into the lid 10.
The upper support plate 40 is provided with a plurality of fitting holes 43 into which the engaging claws 38 can fit, and
A fitting tube 44 into which the support tube 35 can be fitted is integrally provided. Moreover, the dimensions of the fitting hole 43 are such that when the engaging claw 38 is fitted, the lid 10 and the frame body 2 are connected by frictional force.
7, and due to this connection, the filter bodies F ₁ and F _{2 can be opened from the purifying section 9 through the openings 9a and 7} at the same time as the lids 10 and 11 are opened.
It is possible to pull it up through 9a. on the other hand,
The lower support plate 41 is formed in a zigzag shape except for both ends in the longitudinal direction, and a plurality of locking protrusions 45 are protruded from the central part in the width direction corresponding to each trough. Through holes 46 are bored at positions corresponding to the peaks. Each of these locking protrusions 45
A locking protrusion 47 is provided on the upper support plate 40 to correspond to the above, and a connecting rod 42 is provided on the upper support plate 40 in correspondence to each through hole 46 . Furthermore, locking protrusions 4 are also provided in necessary parts other than those locking protrusions 45 and 47.
5 and 47 project from both support plates 40 and 41, and connection rods 42 are also implanted in the upper support plate 40 at necessary parts other than the connection rods 42.

The tip of each connecting rod 42 is formed with a small diameter through a step 48 so that it can be inserted into the through hole 46, and the small diameter portion is spaced from the step 48 by the thickness of the lower support plate 41. A locking protrusion 49 is located at the open position.
is installed protrudingly. Therefore, when the tip of each connecting rod 42 is inserted into the through hole 46 of the lower support plate 41, the lower support plate 41 is inserted into the stepped portion 48 and the engaging protrusion 4.
9, thereby both supporting plates 40, 41
are connected by a connecting rod 42 to form a frame 27.

The filtering material 5 is formed into a plate shape, and the outer surface of the filtering material 5 is provided with a locking protrusion 4 between both support plates 40 and 41.
5 and 47, and is attached to the frame 27 so that the inner surface is wrapped around the connecting rod 42. As a result, the filtering material 5 is closed at one end on the fitting cylinder 44 side with the fitting cylinder 44 facing inward, and the fitting cylinder 4
The other end opposite to 4 is open, and the whole is bent into a wave shape. Moreover, at the other end of the frame 27, a fitting portion 5 having a substantially U-shaped cross section is provided on both support plates 40, 41.
1, 52; 53, 54 are integrally provided, and both ends of the filter material 5 are connected to their fitting parts 51, 5.
2; 53 and 54, thereby maintaining the open state of the filter medium 5 at the other end.

A plurality of small holes 55 are formed in the lower support plate 41 of the frame body 27 at positions that communicate with the inside of the filter medium 5, that is, the inside of the purification chamber 30 when the filter medium 5 is attached. These small holes 55 allow some of the water in the unpurified chamber 31 to bypass the filter media 5 and 6 and flow into the purified chamber 3.
By guiding the water directly into the purification chamber 30, it functions to maintain an appropriate permeation rate of water that passes through the filter medium 5 from the unpurified chamber 31 and flows into the purification chamber 30.
6 becomes clogged, the water absorption force from the water absorption means 4 is transmitted through the small holes 55 into the suction section 8 to maintain the water absorption action in the suction section 8 and the primary filtration action by the gravel layer 2. It can be continued without any problems.

Further, a stopper 56 having a cross-shaped cross section, for example, is integrally provided at one end of the lower support plate 41 at a position corresponding to the lower part of the fitting tube 44. 71 to purification room 3
This prevents the lower end of the rising pipe 71 from being closed by the lower support plate 41 due to being pushed in too far.

The upper support plate 40 of the frame 27 has each engagement claw 3
8 into the fitting holes 43, and the fitting cylinder 4.
The support cylinder 35 is fitted into the lid 10 in the same way as the support cylinder 35 is fitted into the lid 10. On the other hand, at the upper end of the purifying portion 9 in the casing 7, a locking edge 57 that can be engaged with the engaging claw 38 is provided to protrude inwardly, and the lid 10 fitted with the frame 27 is cleaned. When the upper end of the portion 9 is fitted, the engaging claw 38 engages with the locking edge 57. This engagement force is set to such an extent that the engagement state is released when the lid 10 is pulled up by input.

Furthermore, a plurality of notches 59 are provided at the upper edge of one side wall 14 of the purifying section 9, and these notches 59 pass through between the upper support plate 40 and the lid 10 when the lid 10 is attached. A water hole 60 is formed. Therefore, the upper part of the filtration chamber 25 communicates with the inside of the water tank 1 via the water passage hole 60 and the water passage hole 39 of the lid 10.

By fitting the lid 10 to the upper end of the purifying section 9, the filter material 5 connected and held to the lid 10 via the frame 27 is housed in the filtration chamber 25, but at this time, the filter material 5 is removed from the lower support plate 41. Connecting rod 42 protruding downward
The tip of the aquarium 1 contacts the bottom 1a of the aquarium 1. Therefore, the tip of the connecting rod 42 functions as a leg, and the frame 27 is accommodated in the filtration chamber 25 in a state floating above the bottom 1a of the aquarium 1.

Referring to FIGS. 7 to 9 together, a connecting plate is provided at the center of the purification section 9 in the width direction (left and right direction in FIG. 2) between the upper ends of both side walls 14 and 15 of the purification section 9. A portion 61 is provided, and an engagement groove 62 extending in a direction perpendicular to both side walls 14 and 15 is provided on the lower surface of this connecting plate portion 61. On the other hand, engagement slits 63 and 64 are formed in the lower portions of the side walls 14 and 15, respectively, and the connector 29 is supported by these engagement grooves 62 and engagement slits 63 and 64.

The connector 29 basically has a flange 66 integrally provided on the outer periphery of a rectangular cylindrical body 65.
The outer periphery of the water tank 6 is formed to such an extent that it contacts the inner surfaces of the side walls 14 and 15, the connecting plate portion 61, and the bottom portion 1a of the water tank 1. Moreover, there is an engagement slit 6 in the tsuba number 66.
Projections 67 and 68 that engage with the connectors 3 and 64, respectively, are provided in a protruding manner, and a communication hole 69 is provided in order to avoid partitioning the inside of the filtration chamber 25 with the connector 29. Further, the upper end of the flange 66 has the engagement groove 6
2, and the lower end of the flange 66 is fitted with the connector 2.
A notch recess 70 is provided to allow the filtration chambers 25 on both sides of the filter 9 to communicate with each other.

Such a connector 29 connects the open ends of the pair of filter media 5, 6, thereby connecting the filter media 5, 6 endlessly in a horizontal plane. Moreover, these filtering materials 5 and 6 are arranged within the filtration chamber 25 over the entire width of the connecting port 50, that is, between both ends of the respective flow passages 22 in the suction section 8 in the arrangement direction.

Referring again to FIG. 3, the water absorption means 4 includes a riser pipe 71 extending vertically, a discharge pipe 72 connected to the upper end of the riser pipe 71, a pressurized air source 73 such as a small compressor, and the pressurized air source. 73 and an air supply pipe 74 such as a vinyl tube inserted into the riser pipe 71 through the discharge pipe 72 and fixed to the other end of the air supply pipe 74 near the lower end of the riser pipe 71. It consists of a bottomed cylindrical air injection cylinder 75.

The rising pipe 71 is fitted into the support cylinder 35 of the lid 10 and thrust into the purification chamber 30, and its upper end is disposed slightly below the water level l in the water tank 1. Moreover, the rising pipe 71 is formed to have an outer diameter slightly larger than the inner diameter of the support tube 35 in its natural state, and when it is fitted into the support tube 35, the support tube 35 is moved by the action of the slit 36. Since the support cylinder 35 is enlarged, it is held fixedly by the radially inward elastic force of the support cylinder 35. The discharge pipe 72 is bent into a substantially L-shape and is inserted into the upper end of the riser pipe 71 with its discharge port 76 positioned at approximately the same level as the water surface l. The air injection tube 75 is made of a breathable material such as foamable synthetic resin.
The pressurized air is injected into the riser pipe 71 from this air injection cylinder 75 in the form of fine bubbles, and the bubbles are injected into the riser pipe 71.
Rise within 1.

Such water absorption means 4 may be provided only on one side of the purification section 9 as in this embodiment,
Further, they may be provided on both sides of the purifying section 9. However, if the water absorption means 4 is provided only on one side,
The support tube 35 in the other lid 6 is closed with a cap 77 as shown in FIGS. 1 and 2.

Next, the operation of the above embodiment will be explained. The operation of the water absorption means 4, that is, the supply of pressurized air from the pressurized air source 73 to the air injection tube 75 via the air supply pipe 74, causes the air in the riser pipe 71 to A large number of bubbles are generated at the lower end, and as these bubbles rise within the riser pipe 71, an upward flow is generated in the water within the riser pipe 71. Therefore, a negative pressure is generated in the purification chamber 30, and due to the pressure difference between this negative pressure and the lower water pressure in the water tank 1, water is sucked into the filter device 3 after flowing through the gravel 2. That is, after the water flowing through the gravel 2 is primarily filtered by the filtration action of the gravel 2,
Water flows into each flow path 22 of the suction section 8 from the water suction holes 23 and 24, and is further collected from each flow path 22 into a relatively large-capacity collecting chamber 26, and is introduced into the unpurified chamber 31 from there. Note that water is drawn into the unpurified chamber 31 from the water tank 1 through the water holes 39 and 60 from the upper part thereof. A portion of the water in the collection chamber 26 flows into the purification chamber 30 through the small hole 55, and the remaining water passes through the filter materials 5 and 6 and is filtered into the purification chamber 30.
1. In this manner, the water in the aquarium 1 is first filtered through the gravel 2, and then a portion of the water is secondarily filtered through the filter media 5 and 6, and then returned to the aquarium 1.

In this filtration device 3, the inside of the purification chamber 30 defined by the filter media 5, 6 and both support plates 40, 41 is maintained at approximately the same negative pressure, and the purification chamber 30 is maintained at approximately the same negative pressure.
0 is provided across both ends of each flow passage 22 in the arrangement direction, so the negative pressure within each flow passage 22 is approximately the same. In addition, since the distance between the water suction holes 23 is set to become smaller as the distance from the purification chamber 30 increases, the negative pressure on the upper surface of the suction section 8 is maintained almost uniformly over its front surface. Therefore, the speed of water flowing through the gravel 2 is approximately uniform and appropriate over the entire flow range. Therefore, within the gravel 2, chlorella and aerobic microorganisms are encouraged to grow, and these aerobic microorganisms decompose organic matter such as leftover food and feces of ornamental fish.
Clogging of the gravel 2 can be prevented, and chlorella etc. can also be provided as live bait for ornamental fish.

In addition, in the filtration chamber 25, a portion of the water in the unpurified chamber 31 flows into the purification chamber 30 through the small hole 55, so that the speed of water passing through the filter media 5 and 6 can be maintained at an appropriate rate. , can promote the reproduction of the aerobic microorganisms. In addition, since the filter media 5 and 6 are bent in a wave shape and extend vertically, the filtration area can be made relatively large within a limited space and the filtration efficiency can be improved. This prevents air bubbles from accumulating on the outer surface of the container and obstructing the flow.

Furthermore, even if the filter media 5 and 6 become clogged due to use, the flow of water from the collection chamber 26 to the purification chamber 30 through the small holes 55 is not obstructed.
The water absorption action in the water absorption part 8 is carried out without any trouble,
An appropriate amount of water can always flow through the gravel layer 2, so that the primary filtration action by the gravel layer 2 can be continued and performed accurately.

Furthermore, when replacing the filter media 5 and 6 that have become clogged, the lids 10 and 11 at the upper end of the purification section 9
Simply remove and lift the purifying section 9.
The inner filter bodies F ₁ and F ₂ can be lifted above the water surface together with the lids 10 and 11. Therefore, the filter material 5,
If the filter media 6 are removed from the frames 27, 28 and washed, or replaced with new ones, the clogging state can be cleared. After that, the filter media 5, 6 are reattached to the lids 10, 6 via the frames 27, 28. 11, and the lid 1
By charging it into the purifying section 9 together with 0 and 11, the filtration action can be performed again. Therefore, the filtration device 3 can be left in its normal operating state with the suction section 8 buried under the gravel layer 2, and the filter media 5 and 6 in the purification section 9 can be replaced very easily. When replacing the gravel layer 2, there is no risk that the arrangement of the gravel layer 2 or the aquatic plants planted therein will be disturbed or that the roots of the aquatic plants will be damaged.

In the above embodiment, each of the filter bodies is composed of the lids 10, 11, the frames 27, 28, and the filter media 5, 6.
Although two F ₁ and F ₂ are used, it goes without saying that only one set may be provided in the purification section 9. However, in this case, a single filter medium is connected endlessly in a horizontal plane. In addition, the purification section 9 is also
It may be buried inside. Also, the suction part 8
It is not necessary to partition the inside into a plurality of flow passages 22 with partition walls 21.

As described above, according to the present invention, the flat suction part is installed at the bottom of the aquarium so as to be buried in the gravel spread in the aquarium and introduces water in the aquarium through the gravel; A filter body is provided along one side edge of the suction part along substantially the entire length thereof, stands up above the suction part, and houses a filter body therein for filtering water introduced into the aquarium through the suction part. In the filtration device, the filtration device is equipped with a purification section and a water absorption means for circulating the water filtered in the purification section back into the aquarium, in which a gravel layer above the suction section performs a filtration action. The upper wall of the suction section is composed of a high section extending along and adjacent to the purification section, and a low section connected to the high section via a stepped section, and has a plurality of flow channels directly below the low section. and one collective chamber that communicates with one end of the plurality of flow passages directly below the high part, and the lower part has a plurality of chambers that communicate with each other between the flow passages and the inside of the water tank. an unpurified chamber in which a water absorption hole is bored, the filter body is opened in the purification section, and the gathering chamber is opened over substantially the entire length thereof;
a purification chamber communicating with the water absorption means, and a filter material for filtering a part of the water heading from the unpurified chamber toward the purification chamber, and a filter material for filtering the remaining water from the purification chamber. When the water absorption means is activated, the water sucked into each flow path of the suction section through the gravel layer is passed through a relatively large-capacity collecting chamber. Once collected,
From there, part of the water passes through the filter material, and the remaining water bypasses the filter material and can be accurately divided into the purification chambers through the small holes. Therefore, the opening area of the small holes can be adjusted appropriately. By setting these settings, it is possible to control the water passage speed through the filter media and gravel layer to an optimal value, suppressing the growth of harmful anaerobic microorganisms and promoting the growth of useful aerobic microorganisms in the filter media and gravel layer. This can contribute to water quality purification. Furthermore, even if the filter material becomes clogged due to use, the flow of water from the collection chamber to the purification chamber through the small holes is not obstructed, so an appropriate amount of water can always flow through the gravel layer. This is advantageous because the primary filtration action by the gravel layer can be performed continuously and accurately. In addition, the above meeting room is
Since it can be easily formed by simply making the part of the upper wall of the flat suction part along and adjacent to the purification part higher than other parts, the structure of the filtration device can be made special even by the special installation of the gathering chamber. It is not complicated and can contribute to cost reduction.

[Brief explanation of drawings]

The drawings show one embodiment of the present invention; Fig. 1 is a perspective view of the main parts of a filtration device, Fig. 2 is a view taken in the direction of the arrow in Fig. 1, and Fig. 3 is a state in which the filtration device is installed in an aquarium. FIG. 4 is a sectional view taken along the - line in FIG. 2, FIG. 5 is a sectional view taken along the - line in FIG. 2, and FIG.
6 is an exploded perspective view of the lid, frame and filter material, FIG. 7 is a sectional view taken along the - line in FIG. 2, FIG. 8 is a sectional view taken along the - line in FIG. 7, and FIG. It is an exploded perspective view for showing the connection state of a connector and both filter media. F ₁ , F ₂ ... filter body, 1 ... water tank, 1a ... bottom, 2
... Gravel, 3... Filtration device, 4... Water absorption means, 5, 6...
Filtering material, 8...Suction part, 9...Purification part, 18...Low part, 19...High part, 20...Step part, 22...Flow path,
23...Water absorption hole, 26...Collection room, 30...Purification room, 3
1... unpurified room, 55... small hole.

Claims (1)

[Claims] 1 Installed at the bottom of the aquarium 1 so as to be buried in the gravel 2 spread inside the aquarium 1,
A flat suction part 8 for introducing the water in the aquarium 1 through the suction part 8, and a flat suction part 8 that extends along almost the entire length of one side edge of this suction part 8 and stands above the suction part 8, A purification part 9 houses filter bodies F ₁ and F ₂ for filtering the water introduced into the aquarium 1 through the suction part 8, and a purification part 9 in which the water filtered in the purification part 9 is returned to the aquarium 1. water absorption means 4 for
In the filtration device, the filtration device is made to perform a filtration action on two layers of gravel above the suction part 8,
The suction section 8 has an upper wall 12 consisting of a high section 19 extending along and adjacent to the purification section 9, and a low section 18 connected to the high section 19 via a step section 20. A plurality of flow passages 22 are provided directly below the low part 18, and one collective chamber 26 is provided directly below the high part 19, which communicates in common with one end of the plurality of flow passages 22, and the low part 18 includes: A plurality of water suction holes 23 are bored through which each of the flow passages 22 and the inside of the water tank 1 communicate with each other, and the filter body
F ₁ and F ₂ are unpurified chambers 31 which are opened in the purification section 9 and the gathering chamber 26 is opened over almost the entire length thereof.
and a purification chamber 30 communicating with the water absorption means 4, and the unpurified chamber 3
1 to the purification chamber 30, and a small hole 55 for guiding the remainder of the water to the purification chamber 30 by bypassing the filter materials 5, 6. A filtration device comprising: