The bottom filter is a specially created embankment of various natural materials at the bottom of the well. In some cases, such a filter is simply necessary. Our tips site decided to find out what materials can be used for this purpose, which bottom filter is better, when you can’t do without it.
The bottom filter performs a very important function – the water that passes through it into the wellbore is cleared of suspended particles and debris. The filter allows you to get rid of turbidity in water, make it more transparent, clean, and usable. Yes, in some cases, more thorough disinfection and filtration is still required, especially if the water is used for drinking. But without a bottom filter, the well will quickly silt up and the water quality will be very low.
A layer-by-layer embankment at the bottom of the well can be dispensed with only in the following cases:
- The well opened the rocky layer and rested against it. In this case, no powder is needed on top..
- The well opened up a layer of hard fractured clay. You also don’t need bottom protection.
- Water comes exclusively from natural springs and is not clogged with impurities and suspended particles.
In all other cases, a bottom filter in the well is needed.
A wide variety of natural materials can be used to create the bottom filter. The most important thing is that they do not wash out with water over time and can filter it. Let’s list the popular options:
- Quartz sand. It’s a classic. It is large enough not to cloud the water. And it filters fine suspended matter in water very well. Before filling the well, quartz sand must be thoroughly rinsed several times.
- Gravel, crushed stone. Experts advise to use river or granite gravel of medium and large fraction. The radiation background of granite gravel should be checked, it may be high. Slag stone is categorically not suitable, as it contains harmful impurities! Recyclable construction gravel must not be used. Crushed stone and gravel are also washed several times before backfilling to the bottom of the well..
Important! The most popular bottom filter is a layer-by-layer combination of quartz sand and gravel. Sand is poured first, then gravel, then again sand and gravel. Each layer can be about 20-40 centimeters, but much depends on the depth of the well and the water level in it.
An example of arranging a bottom filter made of quartz sand and gravel: 1 – quartz sand; 2 – gravel; 3 – concrete rings
- Jade. Yes, this stone is most often used in the bath. But it works great as a bottom filter. Jadeite disinfects water, prevents sandy loam from rising, cleans water from heavy metals, and serves for a long time. The only negative is that the stone is quite expensive.
- River and sea pebbles of medium and large fraction. A common and affordable option. Unlike gravel and crushed stone, it is enough to rinse the pebbles just once before backfilling..
- Shungite. A unique material, a cross between diamond and graphite. These are frozen drops of petrified oil. Shungite is widely used in filters for water purification, so it will work very effectively at the bottom of the well, purifying water from various harmful impurities. The only drawback of shungite at the bottom of the well is that it will have to be taken out and boiled over once a year. The portal wrote how to clean the well with your own hands. In the case of shungite, this will have to be done more often than usual. In addition, the price of this stone is noticeably more expensive than ordinary crushed stone..
- Zeolite. A porous stone of volcanic origin. A natural sorbent that removes heavy metals and nitrates from water, reducing the radioactive background. Zeolite costs ten times more expensive than jadeite, so the bottom filter will turn out to be elite. In addition, fakes are often passed off as high-quality zeolite..
Separately, you need to talk about the arrangement of the bottom filter using a shield made of pine boards. This option is used when the soil is clayey at the construction site of the well and quicksand may appear.
The shield is made of boards without gaps, flush with the diameter of the well barrel inside. First, the bottom is cleared of clay, a layer of sand is poured, then gravel. Then a shield is lowered onto this substrate, which must be knocked out with wedges so that it does not float. Then again a layer of sand and a layer of crushed stone for reliability. According to experts, such a bottom filter can only wash up very active quicksand. In this case, you will have to level the shield and add the lower layers.