Under Sink Water Purifier: How It Works, Pros and Cons

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Water purifiers have become an absolute necessity in any home in the current scenario. With growing concerns over contamination, it is no more a luxury as it used to be two decades back. 

There are many variants of water purifiers available in the market depending on the manufacturer. Some come cheap and perform the most basic task of purifying the water while others are on the costlier side that comes with added features like adding minerals into the purified water or adding an extra layer of filtration to give added assurance to the users. 

Depending on your preference, all water purifiers fall largely under these three major variants; Reverse Osmosis, Ultra Violet, and Gravity based purifiers. While we are all familiar with the water purifiers that are wall-mounted or a table-top, there is another variant called the under sink water purifiers. This particular variant isn’t as popular as its other counterparts. 

Nevertheless, it does exactly what the more common and popular variants of water purifiers do. The only difference here is that this appliance is installed under the sink. Hence, the name “under sink” purifier. In the case of this particular purifier, it also comes in three major variants; Reverse Osmosis, Ultra Violet, and Gravity Based. In this article, we will discuss in detail particularly under the sink “reverse osmosis” water purifiers. Here we go.

What Is An Under Sink Ro Water Purifier & How Does It Work?

An under sink RO water purifier is a type of water purifier that is fitted in the bottom of the sink. It is directly attached to the pipeline through which the water flows. Like any other water purifier, under sink RO water purifiers are equipped with various water purification processes to remove impurities from the water. This purified water comes through the attached tap from which can be drunk directly. 

The main highlight of this particular water purifier is that it uses the process of reverse osmosis, more commonly known as RO to purify the water. RO works by using a partially permeable membrane that separates ions, unwanted molecules and other larger particles from the water. This process separates dissolved and suspended chemicals and biological elements like bacteria from the water.

 With the advancement of technology, many water purifiers have added features to make the water better in terms of nutrient content in addition to the removal of impurities. Undersink water purifiers have a high rate of water flow as a result of the hydrostatic tank attached to the purifiers. This allows the water purifier to fill containers much faster than the wall-mounted counterparts.

Related reading: Ultimate Guide To Choose The Right Water Purifier For Your Needs

Pros And Cons

One of the biggest advantages of using an under sink RO water purifier is that it saves a lot of space in your kitchen since this device is fitted under the sink. However, all devices come with its benefit and their challenges. We have listed its pros and cons below for our readers to understand if this purifier is the right one for you.


  • As we mentioned earlier, it is a major space saver. You don’t have to contend with its parts getting entangled with other items in the kitchen nor do you have to worry about any of its parts falling off at any point. It is tucked safely under the sink out of sight.
  • These water purifiers come attached to a hydrostatic tank which fills up water much faster than the regular water purifiers.
  • There is no spillage of water as it is attached to the sink. Just place the bottle and wait for it to fill up.
  • It can be attached without difficulty and doesn’t require the fuss of hanging any component on the wall, unlike its wall-mounted counterpart.
  • It contains a hydrostatic storage tank that stores purified water and can be used even if there is no electricity. 
  • Undersink purifiers have the provision for variations in terms of design and functionalities which is not possible with the regular counterparts.
  • It requires comparatively lower maintenance. All you need to check for is the filter in regular intervals. 
  • It does not affect the aesthetics of the kitchen. Only its faucet is visible in the kitchen which brings no evident changes to the look and feel of the kitchen.

Related reading: What Is Minimum TDS For Drinking Water?


  • It requires an electric socket under the sink which can become an issue in certain cases.
  • It is susceptible to mishaps in case water is spilled near the electric socket. This requires added care. 
  • Improper installation of the device can lead to water leakage and improper functioning of the water purifier.

Points To Keep In Mind

Before making the purchase, there are a few things you need to keep in mind to ensure you don’t have to go through any hassle while installing the under sink RO water purifier. After all, you don’t want to spend your hard-earned money on something that you cannot manage. Here is a checklist for you to go through.

  • Maintenance: Pick a device that requires minimal maintenance. Ensure that you change the filter attached to it at regular intervals.
  • Budget: It’s a good practice to understand how much it will cost you on average to maintain it. Replacing parts or simply keeping them functional can cost a certain amount regularly. Purchase only if you can afford it.
  • Clean space: Make sure the space is clean and free from any water leakage. Make sure to clean the space once every few days and check for water leakage.
  • Power supply: You will need to install an electric panel where the device is kept. Ensure the panel is properly installed to avoid a short circuit.
  • Water faucet: Make sure your sink has sufficienr space to fix the tap attached to the water purifier.

Just like its hugely popular counterpart, the under-sink water purifier comes in different variants depending on the type of purifying method you wish to go for. The mechanism of both wall-mounted water purifiers and under sink water purifiers are the same. As a result, they have the same capability in terms of purifying the water. With the advancements we have made in science, there could be many more variants of filters coming up depending on our usage and lifestyle. What you should keep in mind is that having a good water purifier is a must in every household now and merely using bottled water is no more sufficient. It doesn’t matter which variant you prefer as long you get it installed correctly and begin to use it for you and your family. After all, water is Amrit, as they say!

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