Build Daily

Sanitary Engineering

December 12, 2017 00:14

How to choose a water filter

Buying water filters, you need to understand that today it will not be possible to buy a universal device suitable for all types of apartments, because such units simply do not exist. Different water purifiers are designed for different types of pollution. And for each of them a certain method of water purification is used. In addition, different filters have different performance. About how to choose the right device - next.


  • Selection criteria
  • Specificity of water treatment
  • Classification of cleaning devices
  • Hot water cleaning devices

Selection criteria


It is more correct to choose a device for cleaning according to certain criteria. One of them is chemical analysis, through which you can get a quantitative assessment of the degree of contamination of your water. There is a shortened analysis, which is done only for 10-14 indicators. There are also extended options - they are performed on 14-35 indicators. The choice of one or another specificit

y of the analysis depends on the desire and availability of funds. Be that as it may, as a result, you will be issued a certificate that can be shown to experts on filters. The same applies to the purchase of the water filter "Aquafor".

It should be noted that in the market for such equipment, companies that use the analysis of water do not need to select a purification device. They will have enough information about your region of residence. These manufacturers have a certain statistics, with the help of which the manager can quickly select the optimal water filter for your area. But today such companies are not enough. That is why, both for owners of private houses located outside the city, and for residents of city apartments, it is still best not to forget to conduct a chemical analysis before buying a water filter. Which one to choose from, you will decide for yourself.

Another important criterion is the desired amount of water that you want to receive during the operation of the device. Calculate this figure can be quite simple. So, the calculation is taken that on average, a person consumes from 2 to 2.7 liters of water. This number is multiplied by the number of people in the house. The minimum amount of water required per day for the whole family will be obtained. But best of all, if the filter can give out if necessary for a day of water in two or even three times more. The fact is that the fluid needs can not be called uniform. Perhaps, it will be needed more, for example, when the guests arrive.

The issue of water quality is not as simple as it might seem. If you just need to further purify the liquid, by removing a pair of harmful components from it, you need one simple filter. For example, for apartments in high-rise buildings, the "Barrier" water filter is suitable. Very different requirements are imposed on the device, which should give the water maximum purification. For this, one more filter or complex for water filtration, consisting of several devices, is required. To be sure of your choice, you need to understand the methods of cleaning used today.


Managers who sell water filters to identify harmful substances that enter the human body when they drink raw water show experience with a glass of tap water. As a result of electrolysis, the liquid becomes dirty in a short period of time, a layered sediment of a greenish color appears. After this experience, similar manipulations are done with water, purged with a supposedly high-quality filter. Many here are captivated by the fact that as a result of such an experiment, the liquid remains virtually crystal clear. After all, immediately there are thoughts about various health problems associated with poor quality of the supply of water in the water supply. Therefore, people blindly trusting, acquire an advertised device, although in reality it may not be of the best quality.

Specificity of water purification

To find out which water filter to choose for a house, first of all, it is necessary to understand how they work. Below we will consider various methods of water treatment that have found their application in household appliances:

  • The easiest way is to filter, which allows to purify the liquid from various mechanical impurities( for example, sand, large particles of dust and rust).The filtering element for these devices is porous and fibrous materials. As for the performance of such devices, it, like the degree of purification of the device, largely depends on the ratio of the pore diameter of the material and the size of the mechanical particles present in the water being purified. It should be noted that a filtering material whose pore diameter is less than 0.43 μm is able to retain bacterial particles, thereby allowing the water to be decontaminated and not only to be cleaned of mechanical impurities. This applies to instruments from various manufacturers, for example, to the water filter "Fibos", etc.


  • The filters also use the ion exchange method. It involves the replacement of unwanted ions by neutral ones. For example: magnesium and calcium ions can be exchanged for light sodium ions by the specificity of the exchange, which will make the water softer. Highly contaminated liquid in its composition has heavy metals and fluorides, which, if necessary, can also be removed by such devices. In addition, thanks to this method of purification, water is enriched with certain substances, for example, iodine and fluorine. Filters using the ion exchange method need periodic replacement of filter elements and, consequently, a stock of certain reagents is required. When buying such a device, it is necessary to clarify whether it is possible to purchase these reagents as needed. And is there a regime of independent regeneration.


  • Another popular method of purification is sorption. It is the removal of harmful chemicals from the water. This method, for example, can help to remove an unpleasant smell and make the taste of water better. As absorbing materials( sorbents), most filters use activated carbon. Whichever sorbent is used, the area of ​​its contact with water directly affects the cleaning efficiency. To prevent filtering material from accumulating by microorganisms, disinfecting reagents( for example, iodine and silver ions) are applied to its particles. It is worth saying that any sorbent is limited by the amount of contaminants that it can absorb. This concept is called "capacity".Different sorbents have correspondingly different capacities. When this resource wears out, the efficiency of the device decreases. Moreover, such a filter can, on the contrary, pollute the water with harmful substances that it absorbed earlier.


  • Perhaps, one of the best methods of cleaning is the reverse osmosis method. In this case, the liquid is purified by passing through a semipermeable membrane. The pores of such a membrane can reach from 15 to 500 nm. In the construction of such devices, a pump is provided, which serves to create the high pressure necessary for the filtration process itself. Depending on the pore diameter, reverse osmosis filtration can purify the water partially or virtually completely remove any impurities from the water. It is with the help of such instruments that it is possible to obtain fresh water from sea water. The more filter performance, the higher its cost. Therefore, they are often used in large water supply systems, namely, for the final purification of water.

It is very important today not only to clean, but also to disinfect water. For this, for example, ozone and ultraviolet irradiation are used. Sometimes silver ions or iodine are used. When the water is purified by these methods, it must also be passed through the device with a sorbent( for example, activated charcoal).For example, such as the filter for water "Atoll".This is necessary in order to remove the decay products, rust and harmful microorganisms from the liquid.

Classification of cleaning devices

To date, there are many varieties of cleaning equipment. Let us consider in detail some filters for water purification and their photos.

neo_grand( 1)

So, quite popular in everyday life are jar filters. These are the most primitive devices with a small degree of filtration. Their main task is to clean water from chlorine and unpleasant odors. Partly they can make the water softer. Due to the compactness and mobility, such devices can be successfully used at home, in the office and take them on a business trip. One cartridge is usually enough to clean up to 280 liters of water. Therefore, it will have to be changed at least once every 1.5 months. For such devices, the maximum degree of purification is 20 microns.

Of the advantages it is worth noting:

  • Portability.
  • The appliance does not need to be connected to the water supply.
  • It is very easy to use.
  • His work does not need to be controlled.

The disadvantages are:

  • A small degree of cleaning.
  • Small volumes of purified water.

The amount of water resulting from the operation of the device at a time can not be more than the volume of the jug itself, and it is usually small - no more than 2 liters. Cooking food on average requires about 4 liters of water. Therefore, such a device will have to be filled with water for filtration at least two times. This is very inconvenient. Nevertheless, this filter is perhaps the best for those who are limited by their budget, or with small kitchen sizes.


Flow-through filters installed on the sink. They are usually placed next to the tap. To start cleaning, tap water must be fed through an attached flexible hose.

"Strong" sides:

  • Such devices are good because they have good performance. So, for example, in just one minute this water purifier can give up to 1.5 liters of water.
  • In addition, these filters do not require separate tanks for purified water.


  • Such devices take up a lot of space near the sink.
  • It should also be remembered that it will each time be connected and disconnected from the tap after filtration.


Nozzles on the crane. These filters are small in size, which, as is clear from their name, are dressed directly on the tap.

Pros of similar products:

  • The price of water filters is small.
  • Has mobility. It is possible to take the filter with you on the road.
  • A good quality of filtration.


  • The sorbent has a relatively small volume. This makes such devices not always convenient to operate.
  • Low performance. So, one liter can be obtained about only a couple of minutes after the start of filtration.
  • In addition, an additional tank will be required, where all the water that has been cleaned will be collected.

These devices can include a filter for water "Trio".


Flow-through filters, mounted under the sink. They are devices that are built into the water supply. They themselves are usually located under the sink, and on it comes an additional tap, from which will come treated water. Cartridges for this device should not be changed more than once in six months. Let us pass to the performance indicators. Thus, the maximum degree of purification is from 0.05 to 1 micron. Disadvantages, like other types of devices, there are several, but still the main one is considered - the high cost of similar products. Stationary filters are preferred by people who have managed to understand how valuable purified water is for health.


Reverse osmosis systems. This is definitely the best water filter, and that says it all. The liquid that has passed through devices with such a specific purification becomes not only softer and devoid of harmful impurities, such as iron, rust and chlorine, but it is also disinfected, i. E.from it harmful bacteria and viruses are removed. In combination with such filters, there is usually a system of cartridges that allow the initial purification of water. In addition, there is a special membrane and an element for final cleaning of the liquid.

Such devices can also be equipped with a mineralizer, which makes it possible to enrich the water with useful substances, for example, iodine. It, really, becomes useful to health. The maximum purification rate for such devices is 0.0001 microns. Operation is also quite convenient. Change the membrane, for example, can only be once every three years, and cartridges once a year. The purchase of such water purification devices is a luxury, given their cost. But, nevertheless, they pay off fairly quickly. After all, they can forget about the problem of water purification.

Hot water cleaners


Hot water also needs to be cleaned, but simple filters can not cope with this task. Special instruments are needed, for example, filters for water "Expert".The main condition for their work is exposure to high temperatures. To clean hot water, for example, use the so-called main filters, which can be made both from stainless steel, and from heat-resistant plastic. The water is filtered through a fine-mesh metal mesh. Polyester cartridges can also be used for filtration. The mesh cells for cleaning reach 80-320 μm. This system serves only for pre-cleaning. Therefore, it is not effective for filtration of industrial water.

Very convenient when you can quickly and easily clean the mesh in the filter. For this purpose, the devices are usually equipped with an additional crane. For the filtration, nonwoven polyester devices can be used. The dimensions of the cells should then be from 19 to 6 μm. Today, such devices are widely used for high-quality water treatment from various suspended particles( rust, coarse dust, sand or scum).

It is worth mentioning that existing hot water filters can be installed on the cold water main - they will be able to cope with their task without problems. But you can not use conventional units for cleaning hot water. The fact is that they were not designed to work at high temperatures. Hot water can break the tightness of such devices, because of what the device will leak.