Bottom filter for the well: the selection of materials + options for arrangement
If you plan to use well water as drinking water, it will require serious preparation. To get rid of particles of soil and organic matter entering the mine during a set in a bucket, you need to arrange a filter for the well. An inexpensive, structurally simple system will purify, and in some cases even disinfect water. Safety in these conditions is crucial, do you agree?
You will find all about the varieties of well filters and the methods of their construction in the article proposed by us. Its author has scrupulously dismantled all effective types of filtering well schemes. He thoroughly explained to the reader the variants of the device and described the materials approved for use in this matter.
With our help, you will receive detailed answers to questions arising from the owners of sites with a well. Here are some useful tips on caring for bottom filters.Photo and video applications will help faster and easier to perceive information.
Functional purpose of the bottom filter
The bottom filter is a layer-by-layer mound of various natural materials that are not washed out with well water. Water passing through the filter is cleared of debris, harmful impurities and suspended particles present in the well.
The bottom filter device is mandatory in the following cases when:
- protection of the bottom of the well from erosion is required;
- the flow of water is carried out under great pressure;
- fine or silty sand at the bottom of the well;
- a well opens the quicksand;
- protection of blockage-sensitive pumping equipment is necessary;
- the water level in the well is characterized by large differences, for example, when the pump is running or when precipitation occurs;
- water quality is unsatisfactory: turbidity, sediment, unpleasant smell.
The installation of the bottom filter is not necessary in the case when the well has opened hard fractured clays or rock formation. Do not use bottom protection if water comes from natural keys. If the dense bottom of the well is not clogged with impurities and suspended particles, additional filtering is not necessary.
In other cases, to obtain high quality water, the installation of a bottom filter for a well is a mandatory measure.
Materials for arranging a well day
The bottom filter consists of filtering bulk materials, passing through which the water is cleaned by physical and chemical means. By physical cleansing is meant clearing from debris and suspensions, and by chemical - cleansing from impurities and harmful compounds.
Today, you can buy ready-made bottom filters for wells based on silver, activated carbon and river pebbles in the store. Unfortunately, the cost of such filters is quite high, so most owners of wells prefer to make bottom filters with their own hands.
The materials used for the arrangement of bottom filters should meet the following requirements:
- sufficient density and weight so as not to float in the well;
- not subject to rotting, resistance to formation of a mold;
- neutrality, lack of chemical reactions;
- high level of filtration;
- environmental Safety.
As materials for filters installed at the bottom of wells, are used:
"Traditional" quartz sand
This material is easy to find on the banks of rivers and natural lakes. The grains of sand have a diameter of up to 1 mm, the color is yellowish, translucent. Before laying in a well, quartz sand must be rinsed several times. You can do this as follows:
- Pour a layer of sand 5-10 cm into the container and fill with water.
- Mix thoroughly and leave for 30 sec.
- Carefully drain the water, which will remain particles of debris and silt, and the sand settles to the bottom of the tank.
- Repeat 2-3 times until the drained water is clear.
Washing will help eliminate clay particles and organic inclusions.
Large and medium river pebbles
Common bulk material, also found on the banks of rivers. Pebbles of different size, round shape without sharp edges.
Before using as a bottom filter, the pebbles should be washed with clean water. Some people advise treating pebbles with heat by placing them in a kiln for several minutes.
Gravel of natural origin
Loose breed of natural origin, the size of the particles of gravel - 2-20 mm.
Before laying in the well, this material must undergo a thorough multi-stage washing, since due to the impressive number of voids between the components, gravel is able to accumulate clay and silt particles. Slag gravel cannot be used due to the probably high amount of harmful impurities.
Jade - aerobatics
Jadeite or bathing stone is a mineral semi-precious stone of natural origin, which includes silver and silicon. This mineral has many positive properties that allow you to effectively use it for the device of the bottom filter:
- purifies water from heavy metals;
- interferes with the movement of bottom materials (sand, sandy loam);
- does not absorb water, which means it will last a long time.
The disadvantages of this material include the need to purchase it (jadeite is mined in quarries, not the fact that the deposits are located in your region). The cost of the mineral - from 60 rubles / kg.
Shungit - Water Purifier
The material, which is a large particle of petrified oil. Shungite has the ability to effectively purify well water from:
- petroleum products;
- heavy metals;
- organic impurities;
- excess iron (iron taste of water);
- suspensions, turbidity.
Shungite also has a useful property to saturate well water with valuable for living organisms with microelements.
This material is quite expensive in cost, but its use is indispensable for wells located near industrial enterprises and highways.
Zeolite - an elite material
Zeolite is a natural porous material of volcanic origin. It is a natural sorbent that absorbs nitrates and heavy metal compounds.
Helps reduce radioactive background, destroys phenols and other substances harmful to humans, plants and animals. The effectiveness of this material as a bottom filter is expensive - from 600 rubles per 10 kg.
Geotextiles - a pollution barrier
Sometimes for the device of the bottom filter is applied polymer material - high density geotextiles. The peculiarity of this filter is that it perfectly filters physical suspensions without improving the chemical and bacteriological parameters of water.
The use of dense geotextile as the main material for the filter is advisable if a small amount of gas, such as hydrogen sulfide, enters the well.
Many well owners make a serious mistake by using the following materials for the bottom filter device:
- Secondary building gravel. The material obtained by crushing dismantled reinforced concrete structures will absorb water without filtering it.
- Expanded clay. It has a low density and eventually emerges in the well.It emits harmful substances.
- Granite rubble. In most cases, this material has an increased background radiation.
- Construction limestone rubble. Contains a large amount of lime, the excess of which will reduce the quality of well water.
Washed gravel, sand and natural crushed stone are suitable for the installation of bottom filters.
The device of the soil filter at the bottom of the well
An effective bottom filter cannot be created using only one of the above materials, the best option is a multi-layer filter device using several types of materials of various sizes.
There are two types of filter placement: direct and reverse. The choice of one type or another depends on the soil lining the bottom of the well and the pressure of the incoming water. In 9 out of 10 cases, a more efficient reverse filter is applied.
# 1: Direct backfill option
A three-layered straight filter is the type in which the material of the largest fraction is at the bottom, then the middle layer is located - the fraction size is 5-7 times smaller than the first layer, and at the top the third layer is quartz sand or small river pebbles.The thickness of each layer should be 15-20 cm, which means that the entire filter will take 50-60 cm depth of the well.
The procedure for installing a direct bottom filter:
- Preparation of a bottom of a well: removal of garbage, silt and other pollution.
- Filling the bottom with a layer of 15-20 cm of a large fraction: jadeite, zeolite, large river or sea pebbles.
- Filling of the material of the middle fraction: river or sea pebbles, medium gravel, small zeolite, shungite.
- The formation of the upper layer of the fine fraction: quartz sand, small pebbles.
A direct filter is used on flowing soils (together with a shield), as well as on sandy and loose soils with a small pressure of incoming water. In this case, the main function of the direct filter is to carry out a phased purification of water.
# 2: Reverse styling scheme
The return filter is a type of well filter, in which the laying is performed in layers from the fine fraction to the larger filter elements. The main function of the reverse filter is to prevent fine debris and sand from penetrating into the upper layers. Reverse filter protects the bottom of the well from erosion.It is used on sandy and sandy soils with a calm water flow.
The procedure for installing the inverse bottom filter:
- Preparation of a well and bulk materials.
- The filling of the lower fine fraction layer: quartz sand, small pebbles.
- The filling of the middle fractional layer: river pebbles, gravel, zeolite, shungite.
- Coarse coating: large stones over 5 cm, jadeite, pebbles, geotextiles.
As with the direct filter device, the thickness of each layer should be 15-20 cm. All bulk materials before laying in the well should be washed with running water to remove clay particles and organic pollutants.
Types of well shields
The bottom shield is a wooden shield made of planks in the shape of a circle, used in the case when water inflow into the well occurs with great pressure, as well as in the presence of quicksand. The main function of the bottom shield is to protect the bottom and filter from erosion. For installation in the well use two types of shields: wooden and metal (mesh).
Shield wood laying on the bottom
In comparison with metal, wooden boards have the following advantages:
- environmental Safety;
- used wood has bactericidal properties;
- do not corrode;
- lower cost and ease of manufacture.
The wooden bottom shield can be made independently using one of the materials:
- Oak is a long-lasting strong breed that can give a specific bitter taste to water.
- Larch is a durable material that does not affect the quality and taste of well water. Service life is much less than that of oak.
- Aspen - high strength wood, has disinfecting properties, does not rot, has a long service life.
To make a shield, you need to take a few wooden planks and fasten them tightly with stainless steel nails. It is better to connect with wooden dowels, under which counter holes are drilled in advance in adjacent boards. The diameter of the shield should be slightly less than the diameter of the well, for this a circle is drawn, and the extra boards are cut with a jigsaw.
On the entire surface of the shield holes of 5-10 mm are made through which water will flow. To ensure a better circulation of water, the shield should have wooden “legs”; two bars with a thickness of 5-7 cm, on which boards are piled from above, play a role.
The elements of the inverse bottom filter are placed on the shield: first, coarse fraction materials that do not allow the shield to rise under the influence of water flows. In the presence of strong quicksters, the shield will gradually be sucked into the ground, therefore, it will be necessary to install it every 3-7 years.
Metal bottom fixture
The bottom well shield can be made by hand from a metal mesh with a fine-meshed structure. The advantages of such a shield:
- high strength and durability;
- does not affect the taste of water over time;
- reliably filters sand and garbage of various sizes and origins.
For the manufacture of metal shield used stainless mesh with a cell size of not more than 2 to 2 mm. The grid is placed between two identical circles of metal. Circles are cut from sheet iron and correspond to the diameter of the well. The shield is mounted on a layer of backfill of large stones 10 cm thick, fastening is carried out with the help of pins mounted in the walls of the well.
On the grid poured the elements of the bottom filter. It should be noted that the service life of the grid is from 5 to 10 years, with time the metal begins to deform and rust, losing its filtering properties, which means that the mesh shield needs to be replaced.
Wall filter in the well
In the case when the flow of water entering the well is very weak, and filtration is also carried out through its walls, then the device of the bottom filter is not advisable.In this situation, the best option would be to install a wall filter.
To make a wall filter it is necessary at the very bottom of the well (the lower reinforced concrete ring) to cut V-shaped holes located horizontally, where filter elements of coarse concrete are installed.
Filter concrete is prepared using mid-gravel and cement grade M100-M200 without adding sand. The cement is diluted with water until the consistency of the mixture becomes creamy, after which the previously washed gravel is poured into it and mixed thoroughly. The resulting solution is filled with the cut-out holes and leave until solidified.
Care of the bottom filter
Having equipped the bottom filter in the well, do not forget to clean it at least once a year. The technology of cleaning the bottom filter consists of the following steps:
- Extraction of filter elements and bottom shield from the well.
- Bottom shield cleaning or replacement.
- Rinsing or replacing extracted rocks.
- Laying materials in the same manner.
Timely cleaning of the bottom filter will help maintain the conditions for the collection of clean water from the well all year round.
Conclusions and useful video on the topic
The device of the bottom filter do it yourself with the help of materials of different fractions:
The device of the bottom filter using a wooden shield and shungite:
Production of aspen shield for bottom filter on quicksand:
The device of water filters from a well is not a complicated process that can be performed independently without the involvement of specialists and unnecessary financial investments.
The cost of a well filter device depends entirely on which materials you choose as filtrates. With proper installation and timely cleaning of the bottom filter, you will always have access to clean and tasty water.