Pool filters – types, advantages and disadvantages

The mechanical purification of the water reservoir treatment system is made with the help of a filter. It cleans the water from insoluble particles.  

This article discusses all the most moving models for pool water purification. We will help you choose the most Ideal filter discussing on their pros and cons. 

Why is a filter so important in the water treatment process?  

The main purpose of the filtration system is to create high-quality, hygiene and safe water for people. As a result, microorganisms, bacteria and viruses will be destroyed. 

It is necessary to clean the water with chemicals, water care products, disinfection devices, and filters. If these conditions are met, a safe and healthy environment is created for swimming. 

Sand filters for swimming pools  

Sand filters are the most common ones and can be used for both private and commercial projects. The degree of filtration varies depending on the filter element. The degree of filtration of a AFM glass fill is up to 5 microns and the degree of filtration of a quartz sand is 35 microns. 

Sand swimming pool filters, side mounting Sand swimming pool filters, top mounting

Advantages of sand models: 

  • Lifetime of operation – With proper care, timely service (backwashing, replacement of filter element, etc.) sand filters will run for 10-15 years
  • Touchless cleaning. The system is cleaned without any contact with the filtration media inside. The six-position (or four-position) valve system allows you to perform non-contact cleaning. By turning the valve handle to the desired cleaning mode and starting the pump, the filter will self-clean with the backfill and the system will be ready for operation. It is easy to control the degree of contamination due to the integrated pressure gauge which indicate4s the degree of contamination. a quick wash process from 5-15 minutes does the job (depending on the level of contamination)
  • Full automation of the process. With the automatic 6-position valve, the process can be fully automated. 

How to choose the right filter model? 

Sand filters for private pools are selected according to the capacity. Based on the formula, the volume of water must pass completely through the filtration tank in 4 hours. 

An example to the calculation is shown below:  

Pool of 40 m3 of water for private use. 40 m3 / 4 hours = 10 m3 . The required capacity of the filtration system is a minimum of 10 m3/hour. 

Worldwide manufacturers offer purification systems for private facilities that include a filter and a pump. A ready-to-use solution, which is prepared for quick connection. 

As for commercial and public pools, the formula is relatively the same, except for the number of hours. For commercial installations with heavy occupancy, the recommended time during which the entire volume of water must be completely filtered is 2 hours. For children's pools - the limit is reduced to 1 hour. 

It is also necessary to take into account the standard, according to which the height of the filter element should not be less than 1 meter. This is applicable only in the case of replacing the filter of an existing water treatment system. The design of the future swimming pool along with the water treatment system is obligatory if the construction of the pool is in progress.  

What you need to look for while choosing a Sand filter:  

  • Body material: fiberglass, plastic, polypropylene - Models made of fiberglass are the most reliable and durable,
  • Lever Functions: the availability of a six-position or four-position valve.
  • Connections: top or side connection to the circulation system,
  • Measurement of connections: the diameter of the connection. This is especially important for public pools. Large capacity models must be equipped with a valve manifold. The cost is significantly displayed on the bill. The cost of the item will relatively remain the same and is not affected by the size. If you change the diameter by 1 step, it will help you save the budget. 
Multi port valve for swimming pool filter, top configuration Multi port valve for swimming pool filter, side configuration

Bag filters for swimming pools  

Bag filters are used for overhanging swimming pool filters. An overhang model is best for an existing pool shell as it is already built, and there is no possibility to organize plumbing and a technical room for pool equipment.  

Cloth is the filter element. As stated by the manufacturer, the filtration degree of bag filters is from 6 to 30 microns. With repeated washing (2-3 times a month), the fiber tends to stretch, which results in poor filtering process because of stretching.  

In order to maintain the degree of purification, it is necessary to change the filter bags regularly.  

The downside of using a bag filter is that the accumulated dirt can be washed manually under running water. However, some clients tend to use other methods such as a washing machine or a high-pressure washer, which is unhygienic and is never recommended. The washed off dirt should be thrown into a septic tank or sewer, because they consist of harmful bacteria and viruses (it is best to avoid using it in the garden or the sidewalks). It is also best and suggested to have a place organized assigned to just wash the dirt and into the sewer. The manufacturer indicates that bag filters are applicable to private and public use.  

DE swimming pool filters

Diatom filters for swimming pools  

The diatom filters have a purification degree from 1 to 5 microns. They have been proven to take the first place considering the degree of purification. The filter element used is diatomaceous earth and is suggested for private pools only since it has a very small holding capacity and uses many filter elements for the purification (unlike the sand filter or bag filter which has higher holding capacity).  

The price range of these filters is premium. The water filtered in a diatomaceous earth has revitalizing qualities; it is saturated with useful substances. When using diatomaceous earth filters, the degree of filtration is much higher which resulted in remarkable reduction in the usage of chemicals. Diatoms are usually selected on the basis of their capacity.  

Cartridge filters for swimming pools  

This type of filter is used for frame pools, inflatable pools, and in spa baths. The stated degree of purification is up to 10 microns. Cartridge filters are found to be effective for small water volume (2-5 cubic meters). There is a level of inconvenience with a larger amount of water passing through, as it involves manual cleaning under running water. 

Cartridge filters are best suited for private use, and they require regular replacements, sometimes up to 4 cartridges per season. 

Below are the advantages of a cartridge filter: 

Sewer outlets - not required

Low cost

Pool filter cleaning  

In the process of water purification, all kinds of impurities, dirt, small particles and sediment settle in the backfill. Therefore, the washing should be carried out regularly. The frequency of it depends on the type of filter, the intensity of use, and the degree of impurity.  

Make sure that the filter is disconnected from the pump before cleaning. Th sequence of steps may vary according to the type of filter chosen. A check should always be done on the gauge that indicates the level of contamination for regular cleaning. The replacement of the sand can be done as per the instructions in the user manual.  

Pool filtration control  

Water treatment of the artificial pond is regulated by the owner of the device. Depending on the type of filter, power, capacity, the desired degree of purification. It is controlled by special equipment. 

The filtering device status signals are received from special indicators. 

The procedure for programming the device is outlined in a special manual. You can set the filter modes, which will regulate the speed, degree, quality of purification. The capacity and power of the unit depends on the volume of the reservoir. The type of filter is chosen according to the purpose of the reservoir (small indoor or outdoor pools- for saunas, or large reservoirs for public use).