Under Sink RO Water Purifiers – Advantages & Disadvantages!

Water purifiers have become a necessity today because of the highly contaminated water resources.

The release of industrial and human wastes into the water bodies has caused this situation.

Therefore, you find the presence of heavy metals like arsenic, lead, and mercury in addition to the normal TDS (Totally Dissolved Solids).

There are various kinds of water purifiers available in the market. The ‘Under the counter’ or ‘under the sink’ type of water filter is slowly gaining in popularity.

One of the principal reasons is that the kitchens in the nuclear Indian family homes are getting smaller. These water purifiers save a lot of space while doing the job of water purification. Hence, you find many people opting to buy these water filters.

Under Sink Water Purifier – Buying Guide

Let us now look at the simple points to have in mind while purchasing the ‘under the sink’ water purifier.

Easy to install – Normally, all water purifiers are easy to install. The ‘under the sink’ water purifiers are no different in this regard.

Easy on your budget – In addition to providing highly efficient services, the ‘under the sink’ water filters are easy on the budget, both on the purchase and the upkeep front.

Easy to maintain – These water purifiers do not require much maintenance other than replacing the filters every year.

Save space – The modern-day Indian kitchen is shrinking in size. These water purifiers provide the best alternative as you can place them below the kitchen sink.

Good quality models available – Kent and AO Smith are two of the top models that come to mind when you talk Under Sink RO water purifiers. They are the market leaders in other types of water filters as well. 

Types of Under the Sink water purifiers

Basically, you have two types of ‘under the sink’ water filters, the inline filters, and the regular water filters. Let us see the basic difference between the two.

There is not much difference between the two. The inline filters are installed in-line on your normal water source line with push fittings. In the case of the regular filters, you need to split the mains line using a T-connector and install a separate filter tap.

The inline filters are comparatively difficult to install. However, they allow you to keep on using your kitchen tap as they filter the water flowing through this tap as well. In the case of the regular filters, you need to add another tap to the filtered water alone.

Hence, you would have two different taps in the kitchen sink. However, these filters are easier to install.

Normally, you have to opt for a single cartridge filter if you have an inline filter. Some of the modern models do have multiple cartridges. The regular filters are usually multi-stage filters.

Disadvantages of the Under the Sink water filters

It is necessary to know the advantages and disadvantages of any appliance before buying the product. Let us look at some of the disadvantages of these water purifiers.

Like all water filters, they are normally installed at a single point of use. Hence, these filters will purify the water at that particular water outlet alone. In case you wish all your outlets to have access to filtered water, you should install a whole house filter.

Another disadvantage is that you need to install a separate tap while using these water filters. Alternatively, you can have a three-way kitchen sink tap that can dispense hot, cold, and filtered water from a single outlet.

Points to note in mind

These filters are gradually gaining in popularity. Hence, not many people are aware of the functioning of these water purifiers. The following points will be useful to you while looking out for such water filters.

Filtration efficiency

You judge the efficiency of a water purifier by its contaminant removal capacity and the filtered water output. Therefore, it makes sense to opt for water filters that can eliminate the maximum contaminants without compromising on the output flow rates.


Though people say that you will be able to install these filters on your own, it is always better to rely on the professional to do his job.


It is better to opt for filters that do not require much maintenance. Normally, these water purifiers require changing filters alone.


People make the mistake of looking at the initial cost while purchasing water purifiers. You should also factor in the maintenance costs and the costs you are likely to incur for changing the filters at frequent intervals.

Tap compatibility

If you go for an inline filter, there is not going to be an issue at all. However, if you opt for a regular filter, you should go for a three-way tap that can dispense hot, cold, and filtered water from a single location.


The ‘under the sink’ water purifier is a novelty in the Indian market today. It is gradually becoming popular because of its various inherent advantages. The greatest advantage of this water purifier is that it saves a lot of space. It does not require much maintenance other than the regular changing of filters.

However, one should maintain great hygienic values as these filters are placed below the kitchen sinks. These are locations that demand maintenance of high values of hygiene.

Chaithanya Vanjari
Chaithanya Vanjari
I'm Chaithanya Vanjari, the Creator and Editor-in-Chief at KitchenArena. With a decade of experience in evaluating large appliances like air conditioners, washing machines, refrigerators, and various small home devices, I possess the technical expertise needed to thoroughly review and understand the operational complexities of these appliances.


  1. Hi..I’m confusing to choose the under sink or not..somebody’s said that power consumption is more and some water leaking problems are facing…is it correct r nt…pls give best suggestion

    • Power Consumption is the same as normal water purifiers. If the installation is done properly, there will be no water lekages. You can go ahead and purchase under sink RO model but make sure the place you are installing is hygienic and free from insects.

  2. I m so much confused about under sink R O
    which brand is good as the cost is similiar of all approx 20 k
    I thought it saves the space and it is, but quality performance use , how can I know which one is better ,, every brand says there product good .

  3. Hi, thanks and appreciate your effort in helping people like me in making a quick decision.

    I would prefer not to go with RO but just a UV/UF with sediment filter similar to Kent Ultra. Is there any under sink options.


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