We have organized some frequently asked questions related to alkaline ionized water apparatuses into a Q and A page.
We will add or revise parts and update this page when appropriate.

Regarding the apparatus

What is a medical device approval number?
Medical device for home use must be approved, based on the Japanese Pharmaceutical Affairs Law. The device inspection is conducted in terms of ensuring safety, effectiveness and quality, and devices that meet the requirements for the approval are given their own approval number. Commercial products must show this approval number.
Please explain simply how an alkaline ionized water apparatus works.
Alkaline ionized water apparatus (Water Electrolyzer for Home-Use) has an electrolytic cell inside as a core part. In the electrolytic cell, the cathode (positive electrode) and the anode (negative electrode) are separated from each other by an ion-exchange membrane.
When calcium ion-containing potable water which is poured into the electrolytic cell is subjected to the electrolysis with direct current flow, cations such as calcium, magnesium, potassium and sodium ions are pulled toward the cathode, and anions such as chloride, carbonate, sulfate, nitrate ions, etc. to the anode.
Furthermore, the water is electrolyzed on the electrode surface, resulting in the formation of hydroxide ion (OH-) and hydrogen (H2) on the cathode side so that alkaline ionized water with alkaline pH is generated. (In the anode side, hydrogen ion (H+), negative ions, dissolved oxygen (O2), etc. increase, resulting in the formation of acidic ionized water with acidic pH.)
Can you send me product catalogues and pamphlets?
Also, can you introduce me retailers and recommend products?
We are sorry to say that the association's office does not provide catalogs or introduce retailers, products, etc. Links to the homepages of member companies of the Association of Alkaline Ionized Water Apparatus will be available on the Related Links page. So please refer to that page.
When I wanted to buy a spare water purifier cartridge, a retailer suggested me a compatible non-genuine product of an unknown manufacturer. Would there be any problems if I use it?
Only the water purifier cartridge spare certified by the manufacturer should be used for the alkaline ionized water apparatus. A home use medical device approved by the Ministry of Health, Labor and Welfare must have a manufacturing approval as the prerequisite for manufacturing at approved factories
Also as to spare parts such as water purifier cartridges, etc., if parts other than those specified by the manufacturer are used, it may result in a reduced performance or malfunctions, and it may void any after-sales service agreements.

Regarding the process of producing alkaline ionized water

Why do you add a calcium agent?
Is it essential?
A calcium agent is used as an electrolysis-promoting agent (adding a calcium agent improves electric current).
Furthermore, since there are qualitative differences among tap waters in different regions, if the pH of the alkaline ionized water does not reach the specified value (pH9.5), calcium agent must be added.
Please note that the calcium agent should not be used for the purpose of causing higher calcium intake.
Are the calcium agents safe?
The calcium agents (calcium lactate, calcium glycerylphosphate, etc.) are approved as food additives. They are extremely safe so that they are used in bread, flour, noodles, etc.
Can I use the apparatus with groundwater and simple tap water?
If tap waters as well as ground waters meet the standards for drinking water, there should be no problem in principle. However, there are regional differences in the quality of tap water and some groundwaters may be extremely poor in minerals or some others rich in carbonate. It may be difficult for these waters to get a good electrolysis for producing normal alkaline ionized water. In such cases, we would like to suggest you to contact the customer service department of each company for further information.
I am using a water softener. Is it OK to connect it to an alkaline ionized water apparatus?
The water softener is the device to reduce the concentration of mineral components (calcium, magnesium) of tap water, etc. If the water passed through a water softener meets the water quality standards for tap water, and if you confirm that the alkaline ionized water apparatus produces alkaline ionized water with proper pH from the water, there should be no problem. Please check pH according to the instruction manual or ask the water softener manufacturer to check.

Regarding the characteristics of alkaline ionized water

What kind of water is alkaline ionized water?
It is the water with pH 9-10 obtained from drinking waters by the electrolytic reaction at the cathode of the alkaline ionized water apparatus (water electrolyzer for home-use).
Compared to tap water, alkaline ionized water has a higher content of hydroxide ion (OH-) and cations such as calcium, magnesium, etc.
At the same time, hydrogen gas (H2) is also produced as nano-sized bubbles.
Are there any differences between the alkaline ionized waters produced by different products or models from different companies?
If any models has a stated "Medical device approval number (certification number)" on the product body or in the catalog, it means the models have been approved as medical devices for home use.
All of these products have the same basic electrolytic cell structure as well as the basic principle of electrolysis, and produce the alkaline ionized water with the same approved effects.
(Currently, only “alkaline ionized water apparatus” is approved as the home-use device that may produce medically-effective water on the basis of the Pharmaceutical Affairs Law.
Furthermore, since the size, performance, ease of use, and after-sales service system vary depending on the price and manufacturer, for details please check the product catalogs or contact the customer service department or sales office of each manufacturer.
It seems as though alkaline ionized water turns whitish and turbid when poured into a cup?
If the whitish turbidity disappears when the cup is left alone for a little while, then the whitish turbidity is due to hydrogen gas generated during electrolysis or to the mixture of air into the water inside the apparatus. Therefore there is no problem.
If the whitish turbidity does not disappear even when left alone for a little while, then it may be due to the adhesion of calcium. If that is the case, it may be necessary to clean the apparatus, etc. Please contact the customer service department of the apparatus maker.
What is pH?
pH is the index indicating the degree of alkalinity or acidity.
The pH value is expressed by a figure from 0 to 14 indicating the concentration of hydrogen ion (H+) in the water according to the following equation:
pH = -log [H+]
Values near pH7 are neutral, and as the values become closer to 14 they become more strongly alkaline. On the other hand, as the values become closer to 0 they become more strongly acidic.
What is active hydrogen?
Is active hydrogen present in alkaline ionized water?
Can active hydrogen eliminate reactive oxygen in my body?
Are there differences in the amount of active hydrogen present in alkaline ionized water produced by products of different companies?
Alkaline ionized water contains hydroxide ion (OH-), cations (calcium ion, etc.) and hydrogen (H2) due to electrolysis.
According to some research reports, strongly electrolyzed water contains “activated hydrogen” competent for the elimination of reactive oxygen.
However, this kind of research is still in the study stage, and currently no clear conclusions have been obtained regarding what “activated hydrogen” is and whether it may keep being reactive so as to eliminate reactive oxygen inside living bodies. A variety of researches are also on-going
What does alkaline ionized water taste like?
Almost all types of alkaline ionized water producing apparatus can purify tap water since they contain a water purifier competent for eliminating residual chlorine or chlorine odors.
In addition, alkaline ionized water has been evaluated to be tasty and easy to drink.
Is alkaline ionized water hard water or soft water?
Alkaline ionized water has slightly increased water hardness due to electrolysis, but raw waters (potable waters) available in Japan but Okinawa are generally soft water Therefore, alkaline ionized water is also soft water. (Although there is no clear definition, total hardness of around 100mg/L or less is termed soft water.)
The pH does not show alkaline pH when I check it?
Firstly, it seems likely that your home tap water may be somewhat acidic.
Furthermore, if the tap water is rich in carbonate content, it may be difficult for the apparatus to produce normal alkaline ionized water.
We suggest to boil the generated water once in order to volatilize the carbonates. After letting it cool measure the pH.
If the pH indicates alkalinity, it means regular electrolysis was performed by the apparatus.
Please adjust the electrolysis capability according to the instruction manual for the product, or contact the customer service department of the manufacturer.
What is oxidation reduction potential?
In general, “oxidation” refers to the reaction of a substance with oxygen, and “reduction” refers to the reduction of oxygen of an oxidized substance.
Oxidation reduction potential is an index of the ratio of oxidized substances and reduced substances in a solution, and is indicated in units of mV (millivolts) or V (volts).

Regarding the effects of alkaline ionized water

Please tell me the effects and benefits of alkaline ionized water and acidic ionized water.
Drinking of alkaline ionized water has been verified to be effective for improving weak gastrointestinal symptoms (chronic diarrhea, hyperacidity control, indigestion, and abnormal fermentation in stomach and intestines).
Please note that acidic ionized water may be used for face washing but not drinking.
Does drinking alkaline ionized water help improve constipation?
Medical and scientific studies on alkaline ionized water from various viewpoints have been carried out and still are continuing. It was concluded that alkaline ionized water has the effect of improving abnormal bowel movement such as chronic diarrhea or constipation.
Are the effects and benefits of alkaline ionized water still kept after brewing tea with it or storing it for a prolonged time?
The pH of alkaline ionized water is 9.0 to 10.0.
When it is subject to brewing tea, etc. or if it is long stored, the pH value tends to return toward neutral, so it is recommended that fresh alkaline ionized water should be drunk.
Is it effective against diabetes and atopic dermatitis?
Alkaline ionized water was approved under the Pharmaceutical Affairs Law for improvement of gastrointestinal symptoms such as chronic diarrhea, hyperacidity control, indigestion, and abnormal fermentation in stomach and intestines.
Although there are clinical facilities that are using alkaline ionized water for the purpose of treatment of diabetes or atopic dermatitis, such beneficial effects have not been approved.

How to drink alkaline ionized water

What should I be careful when I drink alkaline ionized water?
Please be careful of the following 3 points:
  1. Please avoid to take medicines with alkaline ionized water and persons with achlorhydria should avoid to drink alkaline ionized water.
  2. If you feel abnormal or strange after drinking or if there are no apparent improvement in symptoms despite continued drinking, please consult your doctor.
  3. Persons with chronic symptoms or with weakened physical condition should consult their doctor before drinking alkaline ionized water.
Please tell me how to drink alkaline ionized water.
When you drink alkaline ionized water for the first time, set the pH around 8 to 8.5 and start with drinking a cup of the water in order to get your physical conditions used to it. After about 2 weeks, gradually increase the pH and/or the drinking amount depending on your physical condition. Continuous drinking of 500ml to 1 liter per day was scientifically demonstrated to be satisfactory to get the effects of the water.
For direct drinking, we suggest drinking of the fresh alkaline ionized water with pH ranging from 9 to 9.5.

Regarding the safety of alkaline ionized water

Is it safe for children and elderly people?
For children or elderly people, alkaline ionized water with low pH (around pH8 to 8.5) should be used at first, and as they become accustomed to it the pH value may be gradually increased. In addition, for neonates (up to around 1 year old), since they drink mother’s milk or milk, their intestinal movements are different from those of adults and so alkaline ionized water is not recommended. However, when they start eating the same foods as adults, there would be no problems basically for them to drink alkaline ionized water.
Can I use it to make milk for my baby?
For babies or neonates, we do not recommend alkaline ionized water since their intestinal movements are different from those of normal adults.
Is it safe for pregnant and parturient women?
No reports of specific problems concerning this matter have been made so far. However, if there are any symptoms, please consult your doctor.
When consulting your doctor, please tell your doctor the following 3 points regarding alkaline ionized water:
  1. Improvement effects against gastrointestinal symptoms (chronic diarrhea, indigestion, abnormal fermentation in stomach and intestines, acid control, and acid indigestion) have been approved for alkaline ionized water.
  2. It is a weakly alkaline water obtained by electrolysis.
  3. Contents of minerals such as calcium, magnesium, etc. are higher than those of tap water.
If a person without gastrointestinal symptoms drink it, wouldn’t it neutralize the person’s stomach acid?
Unlike acid-control medicines, the acid controlling capability of alkaline ionized water is extremely mild so that it is hard for the water to neutralize stomach acids to cause harmful effects.
Alkaline ionized water does not show any immediate effect but a protective slow effect by continuing constant drinking.
In addition, there have been so far no reports of physical problems occurring when it was drunk by a healthy person.
Can I drink down medicines with alkaline ionized water?
For drinking down medicines, purified water should be used.
Since alkaline ionized water itself has approved beneficial effects, its use with other medicines should be avoided.
My aluminum product (pots, kettles, etc.) turned black by a long term use of alkaline ionized water. Why?
Normally, aluminum products have undergone alumite processing (anti-corrosion treatment).
If the alumite processed has worn off for some reason, the aluminum substrate becomes exposed and discolorated.
When alkaline ionized water is used with aluminum containers of which aluminum substrate is exposed, precipitation of white aluminum hydroxide may occur. In some cases, the containers may become spotty.
When the aluminum hydroxide is heated, an oxidized aluminum membrane may be formed and become black. (This phenomenon also occurs with tap water, but the alkalinity tends to make the process progress more quickly).
Since the blackened area is an oxidized aluminum membrane, the aluminum containers can be used as ever without problem.. However, since holes may be formed in the exposed aluminum substrate, we recommend to use containers made of a different material (e.g. stainless steel).
Whitish substances have formed and stuck to the bottom and rim of my electric pot when alkaline ionized water has been continuously used in the kettle. Why?
The white substance stuck to the bottom is mostly calcium components come from tap water. The same phenomena may occur even when intact tap water is used, although the formation of the precipitated substance is more remarkable with alkaline ionized water because it has markedly higher content of minerals such as calcium..
The calcium components stuck can be removed using citric acid (food additive available at pharmacies) or a commercial pot cleaner.
When the cleaner t is used, please follow the instruction manual. Periodical cleaning is recommendable. (This cannot be used for aluminum pots.)

Regarding acidic ionized water

What is acidic ionized water used for?
Alkaline ionized water apparatus produces alkaline ionized water at the cathode side and acidic ionized water at the anode side at the same time. The acidic ionized
water has been known to have an astringent effect so that the water can be used for face-washing or washing dishes, etc.
Please note that disinfective effect on athlete's foot or injuries cannot be expected for acidic water.s foot or injuries are not approved for acidic water produced by alkaline ionized water apparatus.
What should I be careful of when using acidic ionized water for washing my face?
Please be careful of the following 2 points:
  1. Persons with delicate or allergic skin should consult their doctor or pharmacist before using acidic ionized water.
  2. If your skin feels abnormal when acidic water is used, stop using immediately and consult your doctor.
What is the difference between acidic ionized water and “strongly acidic electrolytic water” which is used for disinfection?
"Strongly acidic electrolyzed water" is acidic (pH <2.7 or lower) aqueous solution containing hypochlorous acid which is electrolytically generated from a dilute (<0.2%) saline solution (sodium chloride with purity of 99% or higher) by a specific type of electrolysis apparatus. Strongly acidic electrolyzed water was developed in Japan in the late 1980's as disinfectant water. Strongly acidic electrolyzed water-producing apparatus was approved as a medical device for "hand-washing upon surgery" in 1996 and for "antiseptic washing and disinfection of endoscopes" in 1997.
Acidic ionized water and strongly acidic electrolyzed water are different from each other in terms of the electrolysis condition, properties and beneficial effects.


Does cooking rice with alkaline ionized water make it more delicious?
Alkaline pH may hydrolyze rice starch resulting in the production of reduced sugars and pasty starch. These changes may contribute to make the cooked rice more delicious. Various studies are on-going.
However, the use of alkaline ionized water for cooking is a totally different matter from the use for medical purposes, and beneficial effects.
Why can we use strongly alkaline (pH ≥10) water for boiling and stewing whereas we cannot drink it?
When alkaline water is used for cooking such as boiling and stewing, its pH tends to return toward neutral. This is the same as when using sodium bicarbonate, and so there will be no problem.
Please note that effects against gastrointestinal symptoms are expected only when alkaline ionized water is drunk intact. So when it is used for cooking, etc. the effects cannot be expected.
What kind of water should I use to water plants?
There are some reports claiming that acidic ionized water is appropriate for leaves and alkaline ionized water for roots. Please note that there are should be differences depending on plants so that no simple answer cannot be given.
Are alkaline ionized water and electrolytic reducing water different from each other?
There are manufactures who employ their own names for the water generated by their own products. However, if their products have indication of "medical device approval (certification) number", they are all approved or certified as home-use medical device and. The beneficial effects of the generated water are the same.
However, if the products have no indication of approval (or certification) number, it means they are not the approved medical device so that the type and effect of water are not clear.
Currently, among apparatus to treat or process water for drinking purposes, only alkaline ionized water apparatus (water electrolyzer for home-use) have received the approval under the Pharmaceutical Affairs Law as a household-use medical device.
On the other hand, "whether or not it has reducing power" is in the research stage, and currently no clear conclusion has been reached. Therefore, there is no relationship between names and beneficial effects or classification of products.
There are stick-type products that may convert water into reducing water (or active hydrogen water) by just putting them in water, but does this have the same effect?
If the product is labeled as a medical device with an approval number (certification number), then it has been approved as having the improving effect on gastrointestinal symptoms. Currently, however, there are no approved medical devices for which medical effects can be obtained by just putting them in water.
Check whether or not the product in question is labeled with a medical device approval number (or certification number). (There are products with names similar to "alkaline ionized water apparatus", but if there is no number, they cannot be said to have medical effects. so please be careful.)
What is the difference from alkaline ionized water being sold in PET bottles?
Alkaline ionized water with approved medical effects is only water generated by a home-use medical device (alkaline ionized water apparatus) which have approved and certified numbers.
Therefore, water sold in PET bottles under the name alkaline ionized water (or a similar name), cannot be said as having no beneficial effects, but just to be sure, please contact the manufacturer of such water.
It seems likely that there are products using the name “alkaline ionized water apparatus” without having medical device approval/certification. Is this OK?
For home-use alkaline ionized water apparatus, only products of which scientific evidences on safety and effectiveness passed inspection are approved or certified as a medical device. We are not involved with products which have not received this approval or certification.
Industrial-use alkaline ionized water apparatus used at restaurant kitchens, etc. are obviously different from home-use devices. These apparatus are usually used for cooking, but not for medical purposes, and therefore do not need to get approval and certification as medical devices.
Who should I contact if I have other questions about alkaline ionized water?
If you have other questions, please feel free to contact the general affairs office of the Association of Alkaline Ionized Water Apparatus.
For questions regarding performance, after-sales service, etc. you are encouraged to contact the customer service department of each company.

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About alkaline ionized water apparatus

Effects and results of alkaline ionized water

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