We Explain the Differences between various Water Filtering and Processing Systems

Water is not merely water and there are many ways of optimizing its “Aqua” (Latin for water). And, it is easy to lose track of things. Here, various methods of preparation are described – with their advantages and disadvantages.


Filter Systems
1) Pitcher
2) Whole House Water Filter
3) Countertop / Faucet / Under Sink Filter / Shower Water Systems

Water Treatment Systems:
1) Water ionizer with and without filter
2) Reverse-Osmosis technology
3) Distillation
4) Carbonated water devices
5) Swirl filter and levitation
6) UV light
7) Alkaline water concentrate
8) Magnets
9) Oxygen enrichment
10) Ozonated water

Filter Systems

Basically speaking there is NO single filter which can filter out ALL pollutants with 100% success. For the one part, the composition of the aqua and its pollutants is constantly changing while on the other hand no manufacturer can guarantee 100% filtering. However, an aqua which is cleansed of heavy metals to 95% is still better than NO cleansed liquid. Please remember that with all filter systems follow-up costs are always incurred because EVERY filter must be exchanged after a certain period of time. Inform yourself about these costs and how often the filter has to be replaced prior to purchasing.

The following provides an initial overview of common filter systems:

1) Pitcher:

You will have seen this in advertising: aqua is filled into a container at the top, it then runs through the filter and is collected in a pitcher at the bottom. To use it, the liquid is then poured into a glass or saucepan or a similar vessel. This is the simplest and cheapest method of filtering water.

However, there are differences in the performance and in the price of the pitchers. Take the following points into consideration:

  • how often must the filter be changed (what are the follow-up costs?)
  • what does the manufacturer really promise? Does he supply details of what percentage of, for example, heavy metal which can be filtered out? Or, does he only state that some heavy metals can be filtered out?
  • which pollutants are filtered? (Remember that no filter can remove all of them.)
  • when the manufacturer promises to increase the pH value, does he specify to which amount? (Reminder: This will never be so in the case of pitchers.)
  • if he promises to lower the positive ORP figure does he state a specific value? (No, he cannot in the case of pitchers – When the ORP value is lowered it does not automatically mean that it will be negative. A positive ORP value means that there are more molecules here which plunder electrons, a negative ORP value means that there are more molecules which supply electrons and correspondingly trap free radicals in the body. The more negative the ORP value is, the better.)

A further problem with the pitchers is that the filter is often filled with a granulate of activated carbon, however, it cannot be guaranteed that ALL of the water molecules come into contact with this granulate. Even if the activated carbon is well compacted it can nevertheless happen that the water finds its own paths in the filter so that less aqua comes into contact with the carbon and thus less liquid is cleansed.


- can be used directly, no installation is necessary

- even a child can understand how to use this

- fewer pollutants in the water (often, numbers are not given)

- lower acquisition price than for more complex systems


- limited capacity

- most of these do not make the water alkaline and if they do make it more alkaline then they give no specific figure (e.g. no pitcher can promise that it will supply a pH value of 8.5)

- most of them supply no free electrons by means of which free radicals can be caught

- no specific “promises”, i.e., no specific figures regarding the filtering / the pH value / the ORP value

- the oxygen content is not affected

- minerals are not enriched

- the cluster size is seldom changed (clusters are groups of molecules and the larger the groups of molecules in the water the more difficult it is for them to penetrate and exit the cells)

- not all water molecules come into contact with the filter

- it is still unknown how much pollutants are really filtered out when these small filters are used

2) Whole House:

These are larger filters which are mounted in the water supply system through which aqua is fed into the building. The main advantage is that as a result the whole of the water in all of the faucets is automatically filtered. This means that even when you take a shower, you shower with filtered water.

Whole House Filters vary in:

- the number of filters – 3 filters are much better than 1 filter as each filter specializes in a different type of pollutant

- the type of filter, e.g. carbon filter or sediment filter

- the volume of water which it can filter at the same time

- the type of pollutants which can be filtered out


- filter the WHOLE of the water throughout the WHOLE of the house

- often reach a high level of pollutant filtration


- high price of purchase

- installation often requires the service of a specialist

- cannot replace an alkalizing unit, but can provide support
i.e. it does not make the water more alkaline, it does not reduce the ORP value, it does not influence the oxygen content or the mineral content or the cluster size.

3) Countertop / Faucet / Under Sink Filter / Shower Water Systems

All of these four filters can be connected directly to the faucet. In the case of the countertop device a tube leads from the faucet to the filter and out again. In the faucet type, the filter is mounted directly on the faucet and in the under sink filter, the filter is, as the name indicates, under the sink. The shower water system is mounted on the shower head or, respectively, replaces the shower head.

They differ not only in the manner in which and where they are installed but also:

  • in their filter technology (among others there are 3-stage filters, reverse osmosis filters)
    (see below for reverse osmosis)
  • in their size (the devices at the faucet are much smaller than the under sink filter)
  • in their lifespan (some must be replaced less soften than others)
  • in the type and volume of pollutants which they can filter out


- they are normally easy to install (presupposing basic technical knowledge)

- they are not as costly as, for example, the whole house filters

- once they are installed, you have automatically filtered water straight from the faucet

- reduces pollutants, however, each in a different manner


- it can be assumed that in the case of the smaller filters such as, for example, the faucet filters that the volume of pollutants which  are filtered off is not as large as in the case of the more complex systems

- do not increase the pH value (do not make the water more alkaline)

- a filter is necessary for each faucet

- does not reduce the ORP value

- does not reduce the size of the water cluster

- the mineral concentration is not increased

- the oxygen concentration is not increased

Water Treatment Methods

The following provides an overview of the various methods of treatment which are in part used also by the filter systems which have already been described.

1) Water ionizer with and without filter

The favorite to start with: water ionizers are able to make normal tap water alkaline. You can use water of this nature to counteract hyperacidity in the body. It has, however, a number of further advantages which I refer to below and in many articles on this page. These are devices which are connected direct to a faucet (generally located in the kitchen), the water is then fed through an electrolytic chamber and often also through a carbon filter and is treated in this way. If certain pre-filter devices are installed, depending upon the filter used, additional pollutants such as, for example, fluoride can be filtered out. In such cases, it flows initially through the pre-filter device, a carbon filter, and then through the machine so that we have all the advantages of cleansed and also alkaline water. In principle, the machine splits the water into alkaline and acidic water, the acidic flows into the drain and the alkaline water is fed off through an extra conduit and can be immediately drunk.

Kangen ionizer from Enagic

- there are devices without carbon filters and without the possibility of prefiltering so that the H2O cannot be filtered to remove pollutants – be careful to note this when making your purchase!

- higher purchase costs than for example for a faucet filter

- the aqua from only one faucet can be treated and not from the faucets throughout the house and, as is mostly used for drinking or cooking, the water ionizer is generally installed in the kitchen


An ionizer with carbon and prefiltering devices optimizes water better than any other method:

- the H2O becomes more alkaline (in good devices you can select the pH value exactly), as a result creating a counteraction effect on hyperacidity

- the ORP value is very negative, i.e., the water supplies electrons which can capture the free radicals in the body

- the chemical burden is severely reduced by the use of the carbon and prefiltering devices, pollutants can correspondingly be filtered out

- the mineral concentration is increased

- the cluster size, i.e., the size of the water molecule groups, is lowered so that water can better penetrate and exit the cells

ph meter illustration

- the acidic water (from the machine’s second tube) can be used. Aqua with a pH value of 5.5. for example, can be used for the skin and acidic aqua for disinfecting. Very alkaline water with a pH value of 11 cannot be drunk but is helpful in dissolving fat and is thus good for general cleaning and for cleaning articles of clothing

- purchase costs are considerably higher than, for example, only a pitcher, however, these systems are not comparable – you would not compare a bicycle to an automobile...

2) Reverse-Osmosis Technology

In the case of reverse osmosis the liquid is fed through an extremely fine membrane. As a rule, in an osmosis small particles in the water such as salt are well distributed and diffuse through a semi-porous membrane. In the case of the reverse osmosis, however, the process is reversed, i.e., the aqua is pressed through a membrane and the minerals and additives such as pollutants are filtered out. Dissolved materials such as lime are filtered out, gases, however, pass through. By filtering out the lime and the concentration of acidic gas the water will become more acidic while simultaneously poorer in minerals.

Correspondingly, the advantages and disadvantages are evident:


- is good at filtering out pollutants


- makes the water more acidic, the pH value drops

- also filters out the valuable minerals

- has an oxidizing effect, is aggressive, it is necessary to ensure good protection in the supply lines to prevent corrosion

- cannot dissolve waste products in the body (waste products or roughage are acidic and do not dissolve in an acidic environment)

- reverse-osmosis water cannot conduct electricity well and thus cannot be ionized subsequently. There are insufficient minerals for this purpose so that it makes no sense to install such a filter in front of the ionizer

- the ORP value increases, i.e., the reverse-osmosis liquid does not supply any electrons with which free radicals can be captured. On the contrary, it robs the body of electrons (the higher the positive ORP value the worse the case is)

- the oxygen content is reduced

- the cluster size increases, i.e., the water molecules become larger and correspondingly cannot penetrate and exit the cells easily

3) Distillation

Distilled water is nothing other than cooled water vapor. When you allow aqua to boil in a pot and turn to steam and subsequently collect and cool the steam you will end up with distilled water. As some of the products from the water supply lines have a lower boiling point than water some of the materials which you would like to have are also evaporated. For this reason these devices have an activated carbon filter through which the distilled H2O can flow and which will extract the pollutants.


- extracts pollutants

- the clusters (the groups of molecules) are somewhat reduced in size so that the liquid can better penetrate and exit the cells


- it requires a great deal of energy

- it reduces the pH value of the aqua, i.e. it becomes more acidic

- the ORP value increases, there are now more free radicals, i.e., the water has an oxidizing effect

- the oxygen content drops

- good minerals are filtered out in the course of the process

- as a result the liquid possesses poor conducting capability, i.e. distilled water can no longer be used for an ionizer

4) Carbonated Water Devices

There are simple machines which create carbonated water from the aqua from the faucet. The carbon dioxide required for this purpose is purchased in the form of cartridges which are screwed into the device. Some people prefer to drink carbonated rather than still water.


- it has a more refreshing effect, however, this freshness is only faked


- the carbonizing is nothing but carbon dioxide dissolved in the water which we breathe out with every single exhalation. The carbonation makes the aqua more acidic, i.e. it lowers the pH value of the water

- it only seems to refresh to a greater extent, however, the quality of the water is not improved (on the contrary as a result of the acidity it has worsened), thus it only fakes a plus point in this respect

- it achieves nothing, i.e. no pollutants are filtered out, the water is not ionized and it does not become more alkaline (but instead more acidic), it does supply more minerals and the water clusters are not altered. It simply supplies bubbles.

5) Swirl filter and levitation.

In this process the filter generates swirls in special whirl chambers, changing the structure of the aqua, i.e. the clusters (groups of molecules) become smaller in size.

Levitation is also a swirl technology where the attempt is made to simulate the water circulation (rise and fall of the water). The aqua is speeded up greatly in a stainless steel container; the direction of flow is then changed. As a consequence thin layers of liquid with varying speeds meet thus creating a micro-swirl. This in turn can alter the structure of the water.


- the clusters become smaller so that the molecules can penetrate and exit the cells more easily

- the pH value can possibly increase as carbon dioxide can be degassed

- the oxygen content can possibly be slightly higher


- does not filter out any pollutants, the contents remain almost unchanged. It is possible that some gas escapes

- the ORP value does not change

- the mineral content is not influenced

- the water becomes only slightly more alkaline; however, a higher pH value cannot be targeted. You cannot set the device so that the pH value is, for example, 9.0

6) UV light

UV light serves to sterilize the water, a process which is recommendable above all in the case of water from streams, springs or wells. However, tap water is often sterilized. It should be noted, however, that when water stagnates in supply lines, especially when it is warm, this increases the risk that germs form. Therefore when the faucet has not been used for some time allow the water to run before use.


- sterilizes as far as this is really necessary


- has no advantage when the water is sterile

- as far as I am aware, UV light does not change the structure of the water

- no changes occur also in the pH value, the mineral concentration, the oxygen content, or similar

7) Alkaline water concentrate

The concentrate is nothing less than aqua with an extremely high alkaline level to which you can add normal water. This results in an increase in the pH of the normal water. Some providers advertize that this reduces the ORP value (which is a good feature as this means that the free radicals in the water can be captivated).


- it increases the pH value

- some also lower the ORP value, i.e. free radicals in the water are captivated

- the oxygen content is indirectly increased


- it is not possible to target a specific pH value

- as far as I am aware it is unlikely that the ORP value will sink to a negative value and it is also unlikely that through the addition of this concentrate so many electrons are fed into the water that it will suddenly supply electrons by itself

- pollutants are not filtered out

- the mineral content is not influenced

- the cluster size is not influenced

8) Magnets

It is possible to let the water flow over special magnets or to let it flow past them causing the clusters to diminish in size and to reorganize themselves.


- better structuring in the water with smaller clusters


- not otherwise influenced, no change in pH value, pollutants, ORP value, minerals…

9) Oxygen enrichment

If oxygen is added to the water, oxygenated water is the result. As to how much oxygen the body finally absorbs and how much escapes as gas, i.e. simply dissolves in the air – this is something which no-one can state with certainty.


- the aqua contains more oxygen


- the pollutants are not reduced

- the pH value is not influenced

- the ORP value remains the same, i.e. the water continues to rob the body of electrons

- the mineral concentration remains unchanged

- the cluster size remains unchanged

If you wish to drink H2O with a higher oxygen content you can drink alkaline water from an ionizer – it has a higher oxygen content AND simultaneously counteracts hyperacidity. Hyperacidity is often the cause for too little oxygen partial pressure which can be best improved by de-acidifying the body – for example, by means of alkaline water.

10) Ozonated Water
In this process ozone (O3 – a molecule of 3 oxygen atoms) is added to the water. The objective is to increase the oxygen content of the water. The problem, however, is that the ORP value is simultaneously increased, i.e. it has an oxidizing effect and cannot absorb any free radicals. It is in fact itself an „electron robber”.


- the oxygen content is increased


- the water has an oxidizing effect, it robs the body of electrons

- it remains unknown as whether or not the pH value is influenced

- it has no influence on the number of pollutants or on the number of minerals

In view of the number of different systems – what is recommendable?

Quite naturally the optimum system is that of cleansing the whole of the water in the house by means of a whole house water filter AND, for water for drinking and cooking, the additional installation of an ionizer in the kitchen in the supply line in order to obtain alkaline water. If this proves to be impossible, then one must set priorities. Thus it is possible to mount a pre-filtering device in front of the ionizer so that the water from the household supply is filtered to remove pollutants. In this way you will have combined a filtering and an ionizing system with one another. However, you will still have no filter, for example, in the bathroom. Generally speaking, all filter and ionizing technologies are complex systems – you can find a purchasing decision aid for water ionizers here.

Note: Whenever possible do not combine a reverse-osmosis system with an ionizer!
The ionizer requires minerals for the electrolysis; however, these are depleted by the reverse-osmosis technology or the distillation systems so that electrolysis is often no longer possible without the addition of minerals! Some ionizers also allow the addition of minerals and if you combine these systems make sure of their compatibility prior to purchasing!

These information were not written by the American Food and Drug Administration, or any other official authority. This site and its products do not promise to diagnose and cure diseases, or protect you from them. Always consult your doctor when you are sick.