Water filtration steps are a few steps to clean and healthy water, every day. Although tap water often looks clean, it can contain many impurities – whether physical, chemical or biological – that are invisible to the naked eye. This is why water filtration systems based on filtration stages are becoming increasingly popular in homes, restaurants or industrial plants.

In this article we take a look at how the different stages of filtration work!

1.Mechanical filtration – the first protective barrier

This is the most basic and most commonly used stage in filtration stages that removes physical contaminants such as silt, sediment, rust or debris from pipes. Mechanical filters usually take the form of string or foam cartridges.

The filtration accuracy varies from 100 to as low as 1 micron – the smaller the value, the more accurate the filter.

2.Carbon filtration – safe water

Activated carbon filters effectively remove chlorine, organic compounds, pesticides, herbicides, and improve the taste and odour of water. They work on the principle of adsorption – contaminants ‘ stick ‘ to the surface of the carbon.

They are available in two forms:

• GAC (granulated activated carbon) – larger contact surface area,
• Carbon block (CTO) – more thorough filtration, also mechanical.

3.Watersoftening – combating limescale

Hard water contains large amounts of calcium and magnesium, which settle as limescale in kettles, washing machines or heating systems. To prevent this, softeners based on ion exchange resins are used, which exchange calcium and magnesium ions for sodium ions.

If you want to find out more, be sure to take a look at our post ‘What is water hardness’.

4.Reverse osmosis – Purifying even more thoroughly

One of the most thorough methods of water purification. Pressurised water passes through a semi-permeable membrane that traps almost all contaminants – from batteries and viruses to heavy metals and salts and nitrates.

5.Ultrafiltration – an alternative to osmosis

Ultrafiltration is membrane filtration, which works in a similar way to osmosis, but with larger pores (approximately 0.01 microns). It removes bacteria and larger viruses, while preserving the minerals in the water.

6.UV disinfection – light versus bacteria

The UV lamp emits ultraviolet radiation that destroys the DNA of micro-organisms – bacteria, viruses, fungi – preventing them from multiplying. However, it does not change the chemical composition of the water, so it should be used after mechanical and chemical filters.

7.Mineralization – supplementation with valuable minerals

Reverse osmosis water is very pure, but often also sterile – tasteless and mineral-free. Mineralising filters supplement the water with calcium, magnesium, potassium or sodium, restoring its natural taste and nutritional value.

Bottom line – which filtration system to choose?

Choosing the right filtration system depends on a number of factors:

• Water sources (tap, well, rainwater),
• The pollutants we want to remove,
• Water uses (drinking, cooking, whole house),
• Budget and available space.

Often it is best to seek the help of professionals who , after examining the water, will be able to determine which filtration method will be best for us.