Tap water is not transparent, pleasant taste and purity. Often it can not be drunk raw, tea and coffee from it are not so aromatic and rich. Therefore, many people today are considering how to choose a water filter under the sink. After all, this type of water treatment, as experience has shown, turned out to be the most convenient and practical.
It would be a mistake to assume that these devices involve some specific method of water purification. The phrase "under the sink" means only that they are installed there - under the kitchen sink. Pipes suitable for the filter are connected by tapping with water pipes for cold water supply. And the top is a separate tap from which it will be possible to collect purified water.
If there is too little space under the sink, then wall installation of the filtering system is possible - this is also practiced. The presence of a crane gives comfort of use. Framed the kettle - and pour as needed. Or you can immediately pour some water into a cup to drink.
As for the design features of filters with placement under the sink, they can be made in two versions - reverse osmosis systems and flow sorption filters.
1. Flow sorption filters . These are the most simple and inexpensive devices. they are several (from two to four) containers, sequentially interconnected, inside which are filter cartridges. These filters are connected to the plumbing system with a flexible connection. The most convenient and practical way to do this is under the sink. Well, and on top there is a small tap for clean water.
Flasks with filter elements can be from two to four. Each flask contains a cartridge with a specific filler. Some of them carry out mechanical, other sorption purification. Some filters are also equipped with UV disinfection systems. Tap water, passing through all these flasks, is consistently cleaned, at the beginning from mechanical impurities, and then from smaller inclusions. As a result, the smell of chlorine and rust, metallic impurities and pesticides, dirt with sand, and oil products disappear from the water. As well as pathogenic bacteria that are neutralized, are no longer able to cause harm.
Flowing systems, except for city apartments, also use at summer cottages, cleaning insufficient quality well or water collected from a well. Delicious, like a spring, the water becomes transparent and clean. You can cook or wash food.
Device for the main components of the flow filter "under the sink": 1. Water connection unit; 2. Filter prior sorption or mechanical cleaning; 3. Filter of deep sorption purification; 4. Knot for connection of the crane; 5. Finishing filter and air conditioning; 6. Crane. * (The set of filter modules will depend on the specific filter model).
2. Reverse osmosis systems . And yet, deciding which water filter to use for washing, the majority of consumers stop at this option. In one of the modules of this filter is a sensitive membrane that can pass on only the water molecules. And all the impurities contained in the liquid safely retained on its surface, and then washed off.
At first glance, the visual differences with the flow-through sorption filter are not at all visible. The same several connected tanks. Yes, and this filter is mounted in the same way - it is connected under the sink to the water pipes. However, there is a fundamental difference. In addition to flasks with cartridges from sorbents, there is a reverse osmotic membrane in one flask. In addition to this, these cleaning systems contain a tank designed to create a supply of clean water. This is because the rate of passage of water through the membrane is not as high as the rate of passage through the sorption filter.
Prefilters purify water mechanically and with carbon filler. The filter, after the membrane, mineralizes and deodorizes the water.
Perhaps, in the whole world there will be no system more popular than reverse osmosis. The membrane with tiny holes keeps all the harmful substances, which then simply go into the wastewater.
Device of the main nodes of the reverse osmosis system: 1. Mineralizing filter; 2. Post-filter for air conditioning; 3. Module with reverse osmotic membrane; 4. Accumulative capacity; 5. Filter mechanical cleaning; 6. Filter for sorption cleaning; 7. Sorption filter for finishing cleaning; 8. Crane. * (The set of filter modules will depend on the specific filter model).
Let us dwell on the principle of operation of these filters in more detail:
# 1 part. The three initial steps are called the pre-training block. They include three vertical vessels with prefiltration cartridges. This is a necessary operation before membrane cleaning - you need to remove dirt, sand, rust, so that the sensitive membrane does not clog or break. And at the same time from the water goes the smell of chlorine. For this purpose, mechanical filters and sorption carbon filters are used. In some models, the UV module is also used here.
# 2 part. Next comes the fourth step. This is where the "heart" of the system - the membrane. It is made of thin polymer and rolled up in the form of a roll. Its pore size is extremely small and ranges from 1 to 15 angstroms. There are also systems of nano-filtration type. They have larger membrane pores - from 10 to 70 angstroms (because of this, part of the impurities passes on).
# 3 part. Cumulative capacity is equipped with a special membrane that reacts to filling. As soon as the tank is full, the water supply will stop. The volume of this tank is on average about 10 liters. This is enough for a family of three or four people to be provided with water.
# 4 part. Last - the fifth stage is equipped with a carbon-filled post filter. It is needed to completely get rid of the unpleasant taste that may remain.
# 5 part. And so that you can conveniently pour clean water, the installation is crowned with a faucet. It is put on the sink and attached to the storage tank.
That's all. This is the way to produce commercially high-quality water, sold in stores in large and small bottles. And if you put a filter at home, you can enjoy clean water without leaving your own kitchen.
Sorption-type cartridges usually have carbon filler inside. Their purpose - to remove odors, chlorine, phenol.
Ion-type cartridges contain a special resin that helps soften too hard water.
Polypropylene cartridges are used for mechanical purification of water (from pieces of dirt, grains of sand, rust).
Combined type cartridges allow you to get rid of several impurities and harmful substances at once.
In order to understand how to choose a filter for cleaning the water under the sink, you need to know what kind of contaminants are in the water. To do this, it is necessary to make its analysis by typing in a clean (mandatory) bottle with a capacity of one and a half liters of water. And then go to the sanitary epidemiological station or test center. In the first case it will be cheaper, but longer, in the second - quickly, but more expensive.
Examination is carried out very thoroughly, on as many as thirty items. However, all of them can be divided into several general categories:
Norms of impurity content are determined by SanPiN 2. 1. 4. 559-96. After collecting all the necessary information, you can proceed to the final selection of the filter for washing. The main thing is to decide on the number and type of cartridges (for which the analysis was carried out).
Warning! Only by collecting all the information about water problems, you can understand how many and what kind of cartridges should be in the filter for washing.
To determine excessive rigidity, sometimes no expertise is needed. This is noticeable to the naked eye: scum appears quickly in the kettle, calcareous deposits on the sink and toilet, and ugly stains on the washed dishes.
In this case, you should not install a flow-through filter, as it will be expensive to operate and will not give the desired effect. Systems of this type are of course equipped with filter-softeners, but the whole point is that water-softening cartridges will cease to cope with responsibilities too quickly. We'll have to change or restore them with saline. However, harmful impurities will still be successfully filtered out. But it does not protect your kettle from scum.Very often, you can hear negative reviews about this, but in fact, it’s not the filtration system that is to blame, but the one who decided to use it to clean hard water.
But the reverse osmosis system is able to cope with water of any hardness, turning it into soft and tasty. After all, this quality makes the unique coffee and tea, and also improves the taste of all dishes. And the reverse osmosis system removes water from any bacteria, nitrates, antibiotics and eggs of various parasites (for example, Giardia) - cysts.
Only a reverse osmosis system is able to effectively deal with hard water.
If there are allergies in the house or a person who has a weak digestive system, then immunologists strongly recommend antibacterial treatment of water. It is also necessary for older people, small children, someone who recently had been ill and has weakened immunity. And then the choice of a water filter for washing is carried out taking into account these nuances.
In this case, the reverse osmosis filter will help again. Or you can advise a flow-type system equipped with a special hollow fiber filter. It consists of porous (with pores not more than 0.1 micron) tubes, thin and coping well with viruses, bacteria, cysts. Approximately clean the blood plasma in laboratories.
However, mechanical cleaning cannot remove very small bacteria. Therefore, it is necessary to ensure that an ultraviolet disinfectant is present in the filter. The power and throughput of different models of such disinfectors may be different. The more power and the longer the device runs, the better is the cleaning. According to the standard, 16 kJ / cm 2 is enough.
To get rid of iron, chlorine and other chemical impurities, a flow type system is enough (but the water should not be too hard). Filter types for such systems are selected depending on the problems with water.
These can be integrated cleaning filters and carbon filters that trap rust particles, remove turbidity and unpleasant odor. If necessary, it should be ensured that in the system were highly specialized cartridges. These can be cartridges to remove iron or soften water.
Let's start with simpler devices and tell you how to choose flow filters for water under washing.
1. Number of cleaning steps. On most models, there are three or four. In the first case, in a single module, preliminary mechanical cleansing takes place, and then complete after-treatment together with softening. At the finish line is sorption purification. If there are four modules, the water is also decontaminated.
2. Module cartridge life. This is important. After all, it is from 4 to 12 thousand liters (the difference is three times). When the resource has expired, the filter needs to be replaced. Once a year, at least.
3. How many people will use purified water. For a small family, for example, a small volume is enough. And if the system is placed in an office, kindergarten, or for a large (more than five members) family, then a filter is needed for increased water consumption and having a greater resource of replaceable modules. Pay attention to this when choosing the appropriate model.
4. Cost of service. It happens that an inexpensive device has replaceable cartridges so expensive that they make up almost half the cost. Before you buy a particular model, ask about the price of consumables, as well as their presence in the sale.
5. System configuration. Check that there is an installation kit. It includes, in addition to the crane, collector unit and adapters, tubes for connecting modules and connecting to the water supply. Usually attached detailed assembly instructions. To the house master it is quite "in the teeth".
1. Water pressure in the water pipe. To install such a system, you must have sufficient pressure in the plumbing system. Not below 3 - 3.5 atmospheres. And if suddenly it falls short of the required three atmospheres, then you will need to purchase a special pump, which will raise the pressure to the required limit. Some models come with an already built-in pump.
2. Device dimensions and dimensions of the space under the sink. Check to see if the dimensions of the filter allow it to fit under the sink (or on the wall). Do not forget that in this filter there is a storage tank and it may happen that the allocated area is not enough.
3. Check the quality of the container with the membrane. This is the weakest point.It is optimal if there is a lid on top, and it has two sealing rings. And then even with pressure drops, the flask will not crack.
4. The design of the valve. If it is made of metal and its gasket is ceramic, then that is good. Plastic valves quickly break.
5. Cumulative capacity. Cumulative capacity should be selected according to your needs. One person will have enough five-liter tank, if the family has three or four people, then you need to focus on ten or twelve liters. The material of the container is also important. The metal is stronger, but it corrodes, in contrast to the less durable plastic.
6. Pay attention to the price of consumables and maintenance. Be sure to look at the cost (and affordability) of replacement cartridges. That service then did not cost a lot of money.
7. Note the presence of additional cleaning steps. Look at the extra steps for water purification. For example, the presence of an ultraviolet module, a mineralizer, and also a structurizer. They are not provided in all models, but depending on the problems with your water, some modules will be very useful.
When installing a reverse osmosis system, you need to be prepared for a water purification rate of 98 - 99 percent. In other words, we get almost distilled water, which scares some. They say, where do you get the necessary trace elements and salts for a person? They are all removed from the water. So there is such an opinion among some ordinary consumers.
However, medical specialists quite successfully dispelled this myth. Lucidly explaining that water alone does not cover the daily need for mineral substances. And mostly they come to us with a variety of food. For example, to get the right amount of calcium, you will have to drink 10 liters of water per day - a bit too much. The same amount of calcium is contained in - 12 grams of cheese or 75 grams of cottage cheese. Next, we present the data in the table.
|How much is needed per day, mg
|Content in ordinary water, g / l
|Water volume to ensure the daily norm, l
|Possibility of getting from water,%
|The product containing this element
|The weight of the product to ensure the daily norm, g
|0 , 86
So, as you can see, ordinary water is not very suitable for supplying the body with minerals - not a single person can drink it so much (especially to get enough potassium) . And there is nothing terrible in distilled water. You just need to eat right, eating a variety of foods: vegetables, fruits, dairy, beans and so on.
The cartridge will live, regularly working, from three to six months. The frequency of replacement depends on several factors. In particular, how intensively the filter is used on the quality of water coming from the water supply system. So, in the case of a large amount of mechanical impurities, it is often necessary to replace the cartridge made of polypropylene. Which is just engaged in mechanical purification of water.
The membrane in the reverse osmosis system will have to be replaced once every one and a half or two years. The minimum she will serve is the year. And then each manufacturer has its own recommendations regarding the timing of membrane replacement. Note that the membrane usually passes more than 185 liters of water per day. These are solid volumes.
And finally, it is worth remembering that for any type of filters installed under the kitchen sink, one thing is common. For them, it is important for all to replace the cartridges in time. After all, with the exhaustion of the resource, they not only prove to be useless, but can also do harm.