An introduction to how whole house water filters work.

A whole house water purifier is a household water treatment device that is widely used in homes, hotels, and other venues. It works by removing impurities, odours, harmful substances, and bacteria from water through a series of physical, chemical, or biological filtration methods to ensure safe and hygienic water for household use.

Whole-house water filters typically include multiple stages of filtration, each with specific functions to remove different types of contaminants. Below, we'll step through how a whole-house water purifier works.

Primary Filtration Stage: The first stage of a whole-house water filter is usually primary filtration, which removes larger particles of suspended matter, such as sediment, sludge, rust scum, and other solid particles through the use of a physical filter, such as a mesh filter or chip filter. This step helps to protect the subsequent filters, prolonging their service life and reducing the load on the subsequent filters.

Pre-treatment stage: The next stage is the pre-treatment stage, mainly using multi-media filters and activated carbon filters. Multi-media filters usually use substances such as quartz sand, magnetised water treatment agents and activated carbon. They remove chlorine, odours, organics, sediments and heavy metals from the water. Activated carbon filters, on the other hand, focus more on adsorbing chlorine, organics and some heavy metals from the water and improving the taste and odour of the water.

RO Membrane Filtration Stage: RO (Reverse Osmosis) membrane filtration is an important stage in whole house water purifiers.RO membrane is a semi-permeable membrane with a very small pore size of nanometres. When water passes through the RO membrane, it filters out bacteria, viruses, heavy metals, organic matter, colloids, and most dissolved solids, while retaining water molecules and some minerals.The RO membrane works like a sieve, allowing only smaller molecules to pass through and leaving larger molecules on the membrane.

Descaling Stage: Due to the hardness or dissolved salts in the water, RO membranes may become clogged with scale after a period of time and therefore require descaling. In whole-house water purifiers, a neutralised colour layer resin is usually used to soften the water and remove minerals such as calcium and magnesium ions that can lead to scale formation. This step extends the life of the RO membrane and keeps it working efficiently.

Disinfection Stage: To ensure the safety of your home's water, whole-house water purifiers usually also include a disinfection stage to kill bacteria and viruses in the water. The most common methods of disinfection are the use of ultraviolet (UV) lamps or ozone generators. UV light destroys the DNA structure of bacteria and viruses, thus rendering them non-viable. Ozone, on the other hand, is a strong oxidising agent that eliminates organic matter and micro-organisms from the water.

Post-treatment stage: In the final stage of a whole-house water purifier, an activated carbon cartridge is usually set up again to adsorb residual odours, organics and chemicals, providing better quality, safer water at the outlet.

To sum up, whole house water purifiers go through several filtration stages, from primary filtration to particulate filtration, activated carbon filtration, RO membrane filtration, descaling, disinfection and post-treatment, thus removing impurities, odours, harmful substances and bacteria from the water to provide a safe and clean water environment for the family. Although the working principle of whole house water purifier is complicated, it provides convenience and health protection for our life.