Sand and cartridge filter systems

Filtration itself has been known for centuries, and is used in various industries because it is an uncomplicated process that produces satisfactory results.

Sand filtration, as the name suggests, uses sand to purify the water, which is safe for the environment, and the filtration itself works in a closed circuit. In addition, sand filters are very easy to maintain and have a high cleaning accuracy (up to 50 microns).

To ensure that the water in your pool is always clean and clear, it must be constantly circulated and filtered. Just like chemical water treatment with water care products, physical pool water cleaning is one of the most important care measures. Fully assembled and plug-in cartridge filter systems are often used in private pools.

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How does sand filtration work?

We have already learned what filtration is. The second important concept in this system is circulation, i.e. the circulation of cleaned water. Let us take a closer look at this process:  

  • The filter tank contains sand, which acts as a barrier to dirt, and is a settling vessel for any impurities. 
  • In standard operation, pool water is sucked in through the pipe system, and then automatically fed into the control valve. 
  • It is then transported to the upper part of the tank where it is pressed through fine sand. This is where the actual water purification process takes place. 
  • Pollutants are retained by the sand filter, and the water is directed to the lower part of the container, from where it returns to the pool through a control valve and a pipe system. 
  • The entire process takes place in a closed circuit, thus ensuring complete filtration of the pool water. 

Ease of use of sand filters

Filtering your pool water is a must, but it doesn't have to mean a lot of work and cost. The water purification process itself is automatic, and the cleaning of a sand filter is necessary after approx. 4 - 8 weeks of operation.

Dirt builds up in the filter tank, and water flow deteriorates. This results in a reduction of the flow through the filter unit, which can be very easily recognised by the increase of pressure shown on the pressure gauge. To clean the sand filter, simply turn the lever to the "backwash" position, which causes the filter to start cleaning. The watercourse will reverse automatically (the water will flow from the bottom to the top), and the debris is flushed out through the drainage pipe. Please note that the basic requirement for using a sand filter system is the presence of an outlet pipe.

How do cartridge filters work?

A skimmer placed on the surface of the pool sucks water at the first stage of cleaning, while coarser dirt is retained by the skimmer's pre-screen. Then, in the second cleaning stage, the water is forced into the cartridge filter, where fine dirt is deposited. Clean water is returned to the pool via a return pipe. The filter medium made of fine-pore non-woven plastic is the basis for the particularly high selectivity of the filter elements. Dirt can be filtered out of the water by rolling its layer. The life of the filter is determined by the load on the pool water. If the load is large, it must be replaced or cleaned, depending on the cartridge system, as the filter becomes clogged with debris.

To clean the cartridge filter, remove it from the cylinder with the circulation pump off, and rinse it under running water. It is essential to follow the manufacturer's instructions attached. They often recommend replacing the pool filter cartridges every 3-4 weeks. To prevent contamination, regular cleaning intervals must be observed.

Advantages of the cartridge filter for cleaning the pool

Thanks to the high degree of separation of filter cartridges, they also filter the finest impurities from the pool water. However, more frequent cleaning or replacement results in better filtering results.  In contrast to sand filter systems. Water savings are very high here. Cartridge filters do not require backwashing for cleaning, thus avoiding loss of pool water.