JP2000263054A - Water purifier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water purifier capable of preventing the generation or growth of algae in a water tank and of using metal ions as a nutritious source for culturing organisms in the water tank. SOLUTION: A water purifier D1 comprises a water tank 1, a water receiving tank 2, a filtration tank 3, a decolorization tank 10, a pair of electrodes 4, 4, a direct-current power supply, a suction pipe 6, a circulation pump 7, and a return pipe 12. The iron ions eluted to a water receiving tank 2 by electrolysis react with phosphoric acid in water to produce water-insoluble phosphorus compounds, which are flocculated. A part of the flocculated water-insoluble phosphorus compounds floats on water, and the other part precipitates and accumulates in the water receiving tank 2. The control part 20 memorizes a prescribed current value. The control part 20 carries out control of drive of the circulation pump 7 and of a blower 18, and directs to perform constant current electrolysis for keeping the concentration of iron ions in water in the water tank 1 between 0.03 and 1.0 mg/l.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a water purification device,
More specifically, the present invention relates to a water purification device for purifying water in an aquarium for breeding organisms such as seafood, turtles and aquatic insects.

[0002]

2. Description of the Related Art Conventionally, in a water tank for breeding creatures, whenever the water quality deteriorates, the water in the water tank is replaced or a water purification device is provided, and the water is purified by the purification device. I am trying to do it.

In the latter case, the water purification device is
Equipped with a filtration tank, pump water from the water tank into this filtration tank with a circulation pump, etc., and filter through the filtration tank (physical filtration and biological filtration)
It is known that the water is returned to a water tank after the water is discharged. Such a water purification device can remove organic substances such as manure and residual food from fish and shellfish, and other substances such as ammonia.

[0004]

However, in such a water purification apparatus, the content of phosphoric acid and nitrogen in water in the water tank increases due to the organic substances. Then, algae are generated in the water tank and adhere to the wall surface of the water tank. For this reason, not only is it difficult to observe and appreciate the bred fish and the like, but also the dissolved oxygen in the water is reduced, which may cause an oxygen deficiency state. In addition, there is a problem that it is necessary to frequently remove algae or exchange water, which is troublesome.

Further, when artificial seawater is put into a water tank, the concentration of phosphoric acid in the seawater is considerable (several times higher than freshwater).
Algae are generated in the water tank in a short period of time. In addition, feeding more than an appropriate amount of food to the organisms in the aquarium, or increasing the number of organisms at a time and feeding more food, causes the food to float excessively in the aquarium, thereby causing phosphorus in the water. Algae develops in the water tank in a short time even when the acid content and the nitrogen content increase rapidly.

[0006] Regarding the removal of nitrogen, harmful ammonia is decomposed into nitric acid having low toxicity by filtering bacteria such as nitrifying bacteria and nitrifying bacteria. However, there is no definitive means for removing the phosphoric acid content.

One of the nutrients necessary for breeding organisms such as fish is iron (Fe ²⁺ , Fe ³⁺ ). If this iron is supplied into an aquarium, an environment suitable for breeding organisms can be created. It is known that can be.

[0008] For this reason, attempts have been made to sink an iron material in a water tank and use iron ions eluted from the iron material as a nutrient source for living organisms.

However, the amount of iron ions eluted from the iron material varies with the passage of time, so that not only an appropriate amount of iron ions cannot be eluted into the water tank, but also the iron material is oxidized in water and iron rust forms on the surface. When covered, iron ions may hardly elute.

The present invention has been made in view of such circumstances, and an object of the present invention is to remove most of the phosphoric acid content in a water tank, thereby causing algae to grow or to grow in the water tank. It is an object of the present invention to provide a water purification device that can prevent the risk and can supply metal ions stably and use the metal ions as a nutrient source for breeding organisms in a water tank.

[0011]

According to one aspect of the present invention, a water tank for breeding an organism, a water storage tank for storing water in the water tank, and phosphoric acid in water are supplied into the water storage tank. An ion supply unit for supplying iron ions or aluminum ions for precipitation removal, and a control unit for controlling at least the ion supply unit, wherein the control unit removes phosphoric acid in water from a necessary amount for precipitation removal. A water purification device is provided, wherein an ion supply unit is controlled so as to supply excess iron ions or aluminum ions.

The aquarium is filled with seawater or freshwater for breeding creatures (such as seafood, turtles and aquatic insects). The water storage tank is arranged above or on the side of the water tank, and stores water in the water tank.

As the ion supply unit, an iron dissolving device for eluting iron ions by immersing iron pieces in water, or a chemical solution supply device for supplying a predetermined amount of a chemical solution generating aluminum ions. In addition to the above, an electrode including at least one set of electrodes that elute iron ions or aluminum ions by electrolysis and a power supply that supplies power to the electrodes is preferably used.

The control section controls at least the ion supply section of the control of each section of the water purification apparatus, and the iron section or the aluminum ion in excess of the amount required for precipitating and removing the phosphoric acid in the water. The ion supply unit is controlled so as to supply ions.

That is, the control unit instructs the ion supply unit to supply excess iron ions or aluminum ions. Then, a certain amount of the excessively eluted iron ions or aluminum ions is used as a necessary amount for precipitating and removing the phosphoric acid in the water, and the rest is used as a nutrient source for the breeding organisms in the aquarium.

According to another aspect of the present invention, a water tank for breeding an organism, a water storage tank for storing water in the water tank, and disposed in the water storage tank to precipitate and remove phosphoric acid in water. At least one set of electrodes for eluting iron ions or aluminum ions by electrolysis, a power supply for supplying power to the electrodes, and a control unit for controlling at least the electrolysis, and the control unit controls phosphoric acid in water. There is provided a water purification apparatus characterized by performing electrolysis control so as to elute an iron ion or an aluminum ion in excess of a necessary amount for removing precipitates.

The electrodes are, for example, rectangular plates and are arranged in pairs in the water storage tank, and iron ions or aluminum ions are eluted into the water storage tank by electrolysis. A power supply supplies a current for electrolysis to each set of electrodes.

A set of electrodes is, for example, both iron (or aluminum) electrodes, or one is an iron (or aluminum) electrode and the other is an insoluble metal electrode. In the former case, the passivation of the electrode can be prevented by inverting the polarity of the electrode as desired. In the latter case, an iron (or aluminum) electrode is used as an anode, and an insoluble metal electrode is used as a cathode. Here, examples of the insoluble metal electrode include a silver electrode and a platinum electrode. Preferably, the pair of electrodes is fixed to, for example, an electrically insulative electrode holder, and the interval between the electrodes is kept constant.

Iron ions or aluminum ions eluted into the water storage tank by electrolysis react with phosphoric acid (orthophosphoric acid) in water to form a water-insoluble phosphorus compound (Fe (O
H) _x (PO ₄ ) _y or Al (OH) _x (P
O ₄ ) _y ) and coagulate, and partly settles and accumulates in the water storage tank. The deposited phosphorus compounds are periodically discarded.
Therefore, the phosphoric acid in the water in the water tank can be removed in the water storage tank.

[0020] The water purification apparatus further includes a control unit. The control unit controls at least the electrolysis, and controls the electrolysis so as to elute an iron ion or an aluminum ion in excess of a necessary amount for precipitating and removing phosphoric acid in water.

That is, the control unit instructs a power supply for electrolysis or the like to elute excess iron ions or aluminum ions from the electrodes. Then, a certain amount of iron ions or aluminum ions that are excessively eluted is used as a necessary amount to precipitate and remove phosphoric acid in water,
The remainder is used as a source of nutrients for the creatures in the tank.

In the water purifying apparatus according to the present invention, for example, the control section controls the control (the ion supply section of the ion supply section) so that excess iron ions supplied or eluted have a concentration of 0.03 to 1.0 mg / liter in the water tank. Control or electrolysis control).

Here, the iron ion concentration of the water in the water tank is set to 0.1.
The control unit performs the above-mentioned control so that the concentration becomes 03 to 1.0 mg / liter by supplying various amounts of iron ions to the water storage tank or changing the iron ion concentration of water in the water tank in various ways. This is based on the results of an experiment conducted by the inventor to investigate how algae are generated in an aquarium when electrolysis is performed and what effects appear on breeding organisms.

That is, according to the experiment, it has been found that if the concentration is less than 0.03 mg / l, it is possible to prevent the occurrence of algae. If the concentration exceeds 1.0 mg / l, diatoms, green algae, etc. It was not possible to prevent the algae from developing and growing and multiplying, and it was also found that it was presumed that the rearing organisms in the aquarium would be adversely affected by poor growth and disease infection. .

When the water purifying apparatus is provided with such a control unit, the iron ion concentration of the water in the water tank is maintained in an appropriate range to prevent the algae from forming or growing in the water tank. In addition to this, a part of the excessively eluted iron ions can be used as a nutrient source for the living organisms in the aquarium.

The water purification apparatus according to the present invention further includes an iron ion sensor for detecting an iron ion concentration of water in the water tank, and the control unit performs the control (ion supply unit) based on the detection result by the iron ion sensor. Control or electrolysis control).

Here, the iron ion sensor has a detection unit disposed in a water tank to detect the iron ion concentration of water in the water tank. As this sensor, for example, a known sensor or the like that measures ferrous ion concentration by detecting a change in oxygen concentration in a solution containing ferrous ion using the oxidizing ability of iron-oxidizing bacteria is preferably used. . Then, the control unit increases or decreases the amount of ion supply based on the detection result of the iron ion sensor-the value of iron ion concentration of water in the water tank-or maintains the same level of ion supply, Alternatively, an instruction is given to an ion supply unit or a power supply for electrolysis to increase or decrease the degree of electrolysis or to maintain the same level of electrolysis.

When the water purification device includes such an iron ion sensor and a control unit, it becomes possible to automatically perform appropriate ion supply or electrolysis according to the detection result of the sensor. Therefore, it is possible to prevent the algae from forming or growing in the aquarium, and to use a part of the excessively eluted iron ions as a nutrient source for the breeding organisms in the aquarium.

[0029] The water purification apparatus according to the present invention further comprises a feeder for feeding food to the organisms in the aquarium, and the controller detects the amount of the bait supplied to the aquarium by the feeder and detects the amount of the feed. More preferably, the control (control of the ion supply unit or control of the electrolysis) is performed based on the detection result.

As the feeding device, for example, a device provided with a container for storing food, a motor for feeding the food from the container into the water tank, and a controller for controlling the driving of the motor is preferably used. Can be

The control section detects the amount of food supplied into the aquarium by the feeding device. Then, the ion supply unit or the electrolysis is controlled based on the detection result. As an example of control by this control unit, the phosphate ion concentration in the water tank is estimated from the total amount of food supplied to the water tank within a certain period of time by the feeding device, and when the estimated concentration exceeds a predetermined value, ion There are some which give an instruction to operate the supply unit.

In the case where the water purification apparatus is configured as described above, the control section controls the ion supply section or the electrolysis, whereby the appropriate ion supply or electrolysis can be automatically performed. Therefore, it is possible to prevent the algae from being generated or growing in the water tank.

In the water purifying apparatus according to the present invention, instead of the iron ion sensor and the control section as described above, the control section maintains the current value for electrolysis within a certain range by controlling (supplying ions). It is even more preferred to carry out the control of the section or the control of the electrolysis.

That is, in order to maintain the iron ion concentration of the water in the water tank within the appropriate range, one or more current values for ion supply or electrolysis are stored in the control unit in advance. The control unit instructs the ion supply unit or the power supply for electrolysis so that the control unit performs appropriate ion supply or electrolysis based on the one current value or the current value selected by the user.

When the water purification device is provided with such a control unit, it is possible to perform appropriate ion supply or electrolysis, and therefore, it is possible to prevent the algae from forming or growing in the water tank. In addition to this, a part of the excessively eluted iron ions can be used as a nutrient source for the living organisms in the aquarium.

[0036]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Two embodiments of the present invention will be described below with reference to the drawings. The present invention is not limited by these.

As shown in Embodiment 1 Figures 1 and 2 embodiment, the water purification apparatuses D ₁ according to a first embodiment of the present invention includes a water tank 1, a filtration tank 30, a water storage tank 2, the filter tank 3, a decolorization tank 10, and a set of electrodes 4.4
A DC power supply (not shown) for supplying a current to the electrodes 4, 4; an electrode holder 5; a pumping tube 6;
And a return pipe 12. The water tank 1 to the pumping tube 6 to the filtration tank 30 to the water storage tank 2 to the filtration tank 3 to the decolorization tank 10 to the return pipe 12 form one circulation channel.

In order to adjust the flow rate of the circulation flow path, a flow control tank 22 which is another circulation flow path is provided adjacent to the circulation flow path.
Is provided. The flow rate adjusting tank 22 is provided on the downstream side of the filtering tank 30, and introduces water that has passed through the filtering tank 30 through the larger advancing port 30 a and flows to the return pipe 12.

The aquarium 1 is for rearing fish and shellfish and the like, and is formed of a box having a substantially rectangular planar shape. The water in the water tank 1 is pumped into the filtration tank 30 by the pumping pipe 6 and the circulation pump 7. The filtration tank 30 is placed on the inner lid 8 that covers the opening edge of the water tank 1.

The filtration tank 30 is for physically filtering organic matter in water such as fish excrement and residual food, and has a built-in filter (coarse filter) 31 for performing filtration. The filter 31 is a needle-punch type nonwoven fabric made of polypropylene as a raw material (as an example, a basis weight: 400 g / m ² , a thickness of 4.0 mm, and a ventilation volume of 160 c).
c / cm ² / sec).

The water storage tank 2 is provided on the downstream side of the filtration tank 30 so that the water passing through the filtration tank 30 can be transferred to the smaller advancing port 30.
b) to remove phosphoric acid in water. Each of the pair of electrodes 4 in the water storage tank 2 is a rectangular plate-like iron plate, and elutes iron ions for removing phosphoric acid in water by electrolysis. The electrode holder 5 has an electrical insulation property, is attached to the upper ends of the electrodes 4, and keeps a constant distance between them.

The iron ions eluted into the water storage tank 2 by the electrolysis react with phosphoric acid (orthophosphoric acid) in the water to form a colored water-insoluble phosphorus compound (Fe (OH) _x (P
O ₄₎ aggregate becomes _y), partially suspended in the water a part of the other deposited precipitates in the water storage tank 2.

The filtration tank 3 is provided on the downstream side of the water storage tank 2 and is for introducing and removing the water-insoluble phosphorus compound floating in the water and the organic matter such as manure and residual food of fish and shellfish through the advection port 2a. And a built-in filter 11 for removing phosphorus compounds and performing biological filtration. The filters 11 and 11 are formed by laminating a plurality of sheet-shaped nonwoven fabrics of the same needle punch type as the filter 31 using polypropylene as a raw material.

The decolorizing tank 10 is provided on the downstream side of the filtration tank 3 and transfers the water passing through the filter 11 of the filtration tank 3 to the advection port 3a.
Through which the colored phosphorus compound is decolorized and filtered, and has filters 9.9 for filtering. The filter 9.9 is made of polypropylene resin and has a length of about 10 mm, an outer diameter of about 6 mm, and an inner diameter of 3 mm
A large number of hollow cylinders are accommodated in a bag.

The decolorizing tank 10 has a detour 10a projecting toward the flow control tank 22. That is, the decolorization tank 1
When the upstream filter 9 at 0 is clogged, or when a large amount of water flows from the filtration tank 3 into the decolorization tank 10, the water in the decolorization tank 10 passes through the bypass part 10 a and the downstream filter 9. 9 to flow.

Reference numeral 10b denotes an upstream advection port through which water that has passed through the upstream filter 9 flows to the downstream filter 9, 10c and 10c denote overflow ports to the bypass 10a.
0d indicates a downstream advection port, respectively.

The return pipe 12 is provided on the downstream side of the decolorizing tank 10 and the flow rate adjusting tank 22 so as to penetrate the inner lid 8. The return pipe 12 is purified by passing through the decolorizing tank 10 and overflows from its advection port 10 d. This is for returning the water that has passed through the flow rate adjusting tank 22 to the water tank 1.

Reference numeral 13 denotes an outer lid which is covered on the edge of the end wall of the inner lid 8. Reference numeral 14 denotes an electrode fixing plate having an opening. The electrode fixing plate 14 is for inserting a pair of electrodes 4 attached to the electrode holder 5 into the opening and fixing them with screws 15.

Reference numeral 16 denotes a strainer arranged inside the water tank 1 and connected to the pumping pipe 6. Reference numeral 21 denotes a gravel layer disposed at the bottom of the water tank 1. Reference numeral 17 denotes an aeration tube provided at the bottom of the water storage tank 2. The aeration pipe 17 is connected to the water storage tank 2 through an air supply pipe 19 from an air supply blower 18 arranged outside the water storage tank 2.
Compressed air is supplied to the bottom of the electrode 4 and the generated bubbles cause
・ Wash the surface of 4.

Reference numeral 20 denotes a control unit, which is a circulating pump 7
In addition to the drive control of the blower 18 and the electrolysis of the water storage tank 2, elution of iron ions in excess of the amount required for precipitating and removing the phosphoric acid contained in the water of the water tank 1 is performed.

That is, the control unit 20 controls the electrolysis current value to fall within a certain range in order to elute excess iron ions having a concentration of 0.03 to 1.0 mg / liter in the water tank 1 from the electrodes 4.4. Instruct the power supply for electrolysis to keep.

More specifically, the control unit 20 includes:
The iron ion concentration of the water in the water tank 1 is set to 0.03 to 1.0 mg /
In order to maintain the liter, one current value for electrolysis is stored in advance. Then, based on the one current value, the control unit 20 instructs an electrolysis power supply or the like to perform appropriate electrolysis.

This current value is determined by how the concentration of iron ions in the water in the water tank 1 is variously changed, and how the algae are generated in the water tank 1 when electrolysis is performed at various current values in the water storage tank 2. It is based on the result of an experiment by the inventor who investigated what kind of effects would appear on bred animals.

The water purification device D ₁ is provided with such a control unit 20.
So that appropriate electrolysis can be performed,
Therefore, it is possible to prevent the algae from forming or growing in the aquarium 1 and to use a part of the excessively eluted iron ions as a nutrient source for the breeding organisms in the aquarium 1. .

Second Embodiment As shown in FIGS. 3 and 4, a water purification device D _{2 according to a} second embodiment of the present invention is different from the water purification device D according to the first embodiment.
_In addition to the configuration of ₁ , an iron ion sensor 35 immersed in the water of the water tank 1 is provided.

The iron ion sensor 35 includes a main body 35 a mounted on the inner lid 8 in front of the circulation pump 7 and a sensor main body 3.
5a penetrating through the inner lid 8 and penetrating into the water tank 1 and a detection part 35b,
The concentration of e ²⁺ is detected.

Reference numeral 40 denotes a control unit, which is a circulating pump 7
The following electrolysis control of the water storage tank 2 is performed together with the drive control of the blower 18.

That is, the control unit 40 determines the detection result of the iron ion sensor 35-the ferrous ion Fe of the water in the water tank 1.
It instructs a power supply for electrolysis or the like to increase or decrease the degree of electrolysis or maintain the same level of electrolysis based on the value − of the concentration of ²⁺ .

The construction and function of the other parts of the water purification device D ₂ are the same as those of the water purification device D ₁ , and a detailed description thereof will be omitted.

According to the water purification device D ₂ , since the iron ion sensor 35 and the control unit 40 are provided, appropriate electrolysis according to the detection result by the iron ion sensor 35 can be automatically performed. The algae can be prevented from growing or growing in the aquarium 1, and a part of the excessively eluted iron ions can be used as a nutrient source for the breeding organisms in the aquarium 1.

[0061]

According to the first aspect of the present invention, there is provided a water tank for breeding creatures, a water storage tank for storing water in the water tank,
Into this water storage tank, an ion supply unit for supplying iron ions or aluminum ions for precipitating and removing phosphoric acid in water, and a control unit for controlling at least the ion supply unit are provided. The ion supply unit is controlled so as to supply an iron ion or an aluminum ion in excess of the amount required for precipitating and removing phosphoric acid. Therefore, a predetermined amount of iron ions or aluminum ions excessively supplied to the water in the aquarium is used for removing the phosphoric acid in the water, and the algae can be prevented from growing or growing in the aquarium. At the same time, a part of the excessively supplied iron ions or aluminum ions can be used as a nutrient source for the bred animals in the aquarium.

According to the second aspect of the present invention, a water tank for breeding an organism, a water storage tank for storing water in the water tank, and a phosphoric acid in the water are disposed in the water storage tank to precipitate and remove phosphoric acid in the water. At least one set of electrodes for eluting iron or aluminum ions by electrolysis, a power supply for supplying power to the electrodes, and a control unit for controlling at least the electrolysis. Is configured to perform electrolysis control so as to elute an iron ion or an aluminum ion in excess of a necessary amount for removing precipitates. Therefore, a predetermined amount of iron ions or aluminum ions excessively eluted in the water in the water tank is used for removing phosphoric acid in the water, and it is possible to prevent the possibility that algae are generated or multiplied in the water tank. In addition, some of the excessively eluted iron ions or aluminum ions can be used as a nutrient source for the creatures kept in the aquarium.

According to the third aspect of the present invention, the control unit performs the control so that the excess iron ions supplied or eluted have a concentration of 0.03 to 1.0 mg / liter in the water tank. It is configured. Therefore, the iron ion concentration of the water in the aquarium is maintained in an appropriate range, and it is possible to prevent the algae from forming in the aquarium or the algae from growing, and to prevent the iron ions from being excessively supplied or eluted. Some of these can be used as nutrients for bred animals in the aquarium.

In the invention according to claim 4, an iron ion sensor for detecting an iron ion concentration of water in the water tank is further provided, and the control unit performs the control based on a detection result by the iron ion sensor. It is configured as follows. Therefore, it is possible to automatically perform appropriate ion supply or electrolysis in accordance with the detection result of the sensor, and to prevent the possibility that algae may be generated or proliferate in the aquarium, and excessively. Part of the eluted iron ions can be used as a nutrient source for the breeding organisms in the aquarium.

According to the fifth aspect of the present invention, there is further provided a feeding device for feeding food to the organisms in the water tank, and the control unit detects the amount of food supplied into the water tank by the feeding device. In addition, the control (the control of the ion supply unit or the control of the electrolysis) is performed based on the detection result. Therefore, by controlling the ion supply unit or the electrolysis by the control unit, it is possible to automatically perform appropriate ion supply or the electrolysis, and to prevent the possibility that algae are generated or proliferate in the water tank. can do.

In the invention according to claim 6, the control unit is configured to perform the control by maintaining a current value for supplying ions or electrolysis within a certain range. Therefore, it is possible to perform appropriate ion supply or electrolysis, prevent the algae from forming or growing in the water tank, and remove a part of the excessively eluted iron ions from the water tank. It can be used as a source of nutrients for domestic creatures.

[Brief description of the drawings]

FIG. 1 is a front sectional view of a water purification device according to Embodiment 1 of the present invention.

FIG. 2 is a configuration explanatory view of an upper part of the water purification device of FIG. 1 as viewed from above.

FIG. 3 is a front sectional view of a water purification device according to Embodiment 2 of the present invention.

FIG. 4 is a configuration explanatory view of an upper part of the water purification device of FIG. 7 as viewed from above.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Water tank 2 Water storage tank 3 Filtration tank 4 Electrode 7 Circulation pump 9 Filter 10 Decolorization tank 11 Filter 20 Control part 30 Filtration tank 31 Filter 35 Iron ion sensor 35a Main part 35b Detection part 40 Control part

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2B104 CA01 CF01 CF28 EF09 4D038 AA05 AB03 AB46 AB47 BA04 BA06 BB10 BB17 BB18 BB19 BB20 4D061 DA06 DB09 DB19 DC13 EA06 EB05 EB19 EB27 EB28 EB30 EB31 GC30

Claims (6)

[Claims] 1. A water tank for breeding an organism, a water storage tank for storing water in the water tank, and an ion for supplying iron ions or aluminum ions for precipitating and removing phosphoric acid in the water into the water storage tank. A supply unit and a control unit for controlling at least the ion supply unit, wherein the control unit supplies ions so as to supply an iron ion or an aluminum ion in excess of a necessary amount for precipitating and removing phosphoric acid in water. A water purification device characterized by controlling a part. 2. A water tank for breeding organisms, a water storage tank for storing water in the water tank, and iron ions or aluminum ions disposed in the water storage tank for precipitating and removing phosphoric acid in water. At least one set of electrodes eluted by electrolysis, a power supply for supplying power to the electrodes, and a control unit for controlling at least the electrolysis are provided. A water purification apparatus for controlling electrolysis so as to elute excess iron ions or aluminum ions. 3. The water purification apparatus according to claim 1, wherein the control unit performs the control such that excess iron ions supplied or eluted have a concentration of 0.03 to 1.0 mg / liter in the water tank. 4. The apparatus according to claim 1, further comprising an iron ion sensor for detecting an iron ion concentration of water in the water tank, wherein the control unit performs the control based on a detection result by the iron ion sensor. The water purifier according to any one of the above. 5. A feeding device for feeding food to an organism in the aquarium, wherein the control unit detects an amount of food supplied into the aquarium by the feeding device, and performs the control based on the detection result. The water purification device according to any one of claims 1 to 3, wherein the water purification is performed. 6. The water purification apparatus according to claim 1, wherein the control unit performs the control by keeping a current value for supplying ions or electrolysis within a certain range.