How do water filters work

Water filters are required as clean water is a necessity in every household. An average human being requires 30-40 liters of clean water every day for various purposes like drinking, bathing, cooking, etc.

As per a recent World Health Organization (WHO) report, globally, close to 2 billion people use drinking water sources contaminated with feces. It is found out that contaminated drinking water causes around half a million deaths every year due to diarrhea.

In this article we will understand in-depth why do we need a water filter, how exactly does a water filter work & what is it made up of. Let us have a closer look!

Why use Water Filters?

How do water filters workThe water that is supplied to us by the municipality or corporations undergoes initial treatment at the purification plant. However, until it reaches our household, it passes through a network of pipes, channels & feeder lines. As a result, in this process, it undergoes contamination with substances like Lead, Chlorine, Rust, Heavy Metals, Viruses & Bacteria, etc.

In fact, at many purification stations itself, Chlorine is used to treat the water. Recent studies have suggested that drinking water with a high level of Chlorine in it causes several diseases.

The process of purifying the water using a water filter removes all these harmful contaminants, thus making the water safe for human consumption.

How do Water Filters Work?

There are multiple types of water filters available in the market. The mode of working of each type of filter differs depending on the technology they use.

Some of the most common water filters & their working mechanisms are mentioned below…

Mechanical Filters

These filters remove physical particles like dirt, stones, rust, etc. They may use anything like a basic mesh to a ceramic filter to remove substances from water. They are usually marked with a rating like 0.5 Micron, 1 Micron, 5 Micron, etc. depending on their ability to remove the type of fineness of particles present in water.

They are not so popular nowadays as they remove only the physical contaminants present in water. They do not work on harmful contaminants like bacteria & viruses which are not visible in the water.

Activated Carbon Filters

These are one of the most popular water filters across the globe, mainly due to their low prices yet effective mechanism. They use activated carbon to block harmful contaminants present in water.

They work on the principle of ‘Adsorption’ in which undesirable constituents are trapped activated carbon granules when water passes through them. They are ideal for removing substances like Chlorine, sediments, etc. You can check here for the price.

Ion Exchange Filters

As the name suggests, these filters are made up of substances that exchange ions present in water with other ions. Many a time, it is used in conjunction with other filtration techniques to remove the hardness of the water. The water passes to further filtration systems to filter the water and remove the present harmful contaminants.

They are mainly used for hard water which consists of Calcium & Magnesium. When water flows through these filters, these ions present in them are exchanged with Sodium, thus making the water ”soft’. Though, it significantly reduces substances present in water; the Sodium will be released in water, thus making the water slightly salty.

Ultra Violet Filters

Ultraviolet water filters are simple, safe for the environment & are extremely effective for removing harmful contaminants like bacteria from the water. UV rays of different frequencies are made to penetrate in water. When water is subjected to these rays, they kill all types of bacteria & viruses present in the water and make it up to 99.9% free from any microorganisms.

UV filters are usually used in conjunction with other filters are activated carbons or RO filters as they are effective for killing microorganisms present in water but does not work on contaminants like Chlorine, heavy metals, etc. UV filters work without introducing any chemicals in the water or without altering the taste or odor of water.

Reverse Osmosis Filters:

These are the most popular water filters today. They are extremely effective in removing harmful contaminants from the water & are easy to install. They are also very cost-effective and require minimum maintenance.

Reverse Osmosis filtration process is quite simple. Water is pushed through a semipermeable member under pressure which removes the impurities present in it. They are also very effective in removing contaminants fully dissolved in water like Chromium & Fluoride.


We hope you would have got a fair idea of what are the various types of water filters available in the market and how they work.

Before you select an ideal filter, make sure you check what the kind of water that is being supplied to you and then determine which type of filter would be the most ideal for your requirements is.


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