Under The Sink Vs Normal Wall Mounted RO Water Purifiers – Which is better?

Under sink and countertop water purifiers take different approaches to filtering water for drinking and cooking. This comparison examines the key differences in installation, capacity, maintenance, filtration performance and cost to determine which system works best for your needs.

How Under the Sink Water Purifiers Work

Under sink water purifiers, also known as inline water filtration systems. This type of water purifier are installed out of sight under the kitchen sink and connected directly to the water supply line. This allows them to filter water at the point of use while taking up no counter space.

Aquaguard UTC RO+UV+MTDS installed under the sink

Most under sink systems use reverse osmosis as the primary filtration method.

Benefits of Under the Sink Water Purifiers

  • Space saving – This type of water purifier Installed under the sink in the cabinet, save valuable counter space.
  • Hidden, seamless design – The under-sink location gives a clean look compared to countertop units.

How Normal Water Purifiers Work

Normal or countertop water purifiers sit visibly on the kitchen counter or can be wall mounted. They are not connected directly to the water line, but instead work batch-wise to filter water that is poured into their reservoir.

Aquaguard Sure water purifier installed wall mounted

Countertop purifiers commonly use a combination of RO, activated carbon filters and UV light to remove contaminants like chlorine, particulates, metals, microbes and odours from a fixed amount of water at a time. The water passes through the filtering media and is stored in a tank ready for dispensing.

Benefits of Normal Water Purifiers

  • Easily accessible clean water – The stored purified water is ready to drink.
  • Flexible installation – They can sit on counter or be mounted on wall.

Comparison of Under The Sink and Normal Wall Mounted RO Water Purifiers

Here is a comparison table of the Under the Sink Aquaguard UTC RO+UV+MTDS and the normal water purifier Aquaguard Sure Delight NXT 6-Stage. It could help you understand the basic technical differences between them.

FeatureAquaguard UTC RO+UV+MTDSAquaguard Sure Delight NXT 6-Stage
Weight10.2 kg5 kg (approx)
Purification TechnologyRO+UV+MTDSRO+UV+UF
Dimensions (WxDxH) mm275 x 285 x 195320 x 270 x 480
Installation TypeUnder the counterWall mounted / table top
Storage Capacity8 litres6 litres (Approx)
TDS Range1 to 2000 mg/L++0 – 2000 mg/L
Input Water Pressure0.3 to 3.0 kg/cm²0.3 to 3 kg/cm²
Input Water Temperature10°C – 40°C10 – 40°C
Input Water Chlorine (Max)0.2 mg/litre0.2 mg/L
Input Water Turbidity (Max)5 NTU5 NTU
Input Water Iron (Max)0.1 mg/litre0.1 mg/L
UV Lamp Power4 watts4 Watts
Life of UV Lamp5000 burning hrs5000 burning hours
Power Consumption48 watts40 watts (max)
Operating Input Voltage150 VAC to 280 VAC, 50 Hz150 – 250 V AC / 50 Hz


Installing an under sink system requires professional plumbing assistance, while countertop filters are simple DIY setups.

Under sink purifiers necessitate complex connections to existing kitchen plumbing lines that are best handled by a knowledgeable plumber. The installation process typically takes 1-2 hours. Expect fees of ₹1500 or more for this professional expertise in addition to the system cost.

In contrast, countertop filters only need to be unpacked, placed or mounted in the desired location, and plugged into a power outlet. An adapter connects the water inlet without plumbing work. The entire setup takes a homeowner just 10-15 minutes with no special skills required.

SystemInstallation TimeExpertise NeededCost
Under Sink1-2 hoursPlumber₹1500+ fees
Countertop10-15 minutesNoneNo added cost

For DIYers who want to get their filtered water solution up and running without pros, countertop systems offer fast, simple setup. Under sink installs require paying for plumbing help.

Space and Aesthetics

Since under sink systems are hidden away, they free up counter space in the kitchen for other uses. Their lack of visual clutter offers a seamless, clean look.

Normal purifiers take up permanent counter space or wall space, though some compact designs have smaller footprints. Their visible water tanks can impact kitchen aesthetics.

Capacity and Flow Rate

The capacity and flow rate of purified water differs greatly between continuous under sink systems versus limited capacity countertop tanks.

Under sink systems utilize direct connection to plumbing to produce a steady, smooth flow of filtered water on demand, unlimited by tank size. This allows production of as much water as needed for drinking, cooking, or other uses.

Countertop purifiers store a fixed amount of treated water in internal tanks that typically hold 1-2 liters. This restricted capacity means frequent refilling downtime as the system must stop purified water production to allow the tank to slowly refill after it’s emptied. Waiting occurs until the next batch is ready.

SystemCapacityFlow Rate
Under SinkUnlimitedContinuous steady flow on demand
Countertop1-2 litersFixed by tank size, interrupted flow

For large families, under counter RO systems provide continuous filtered water output keeping pace with demand. Countertop units work well for individual use but may involve frequent waits during tank refilling.

Annual Maintenance Cost

Under the sink R0+UV Vs Normal R0+UV Water Purifier annual maintenance cost.

FeatureUnder Sink RO+UVNormal RO+UVNotes
Pre-filter₹400 – ₹1,000₹400 – ₹1,000Typically replaced every 6-12 months
Sediment filter₹500 – ₹900₹349 – ₹600Typically replaced every 6-12 months
RO membrane₹799 – ₹3,000₹850- ₹2,500Typically replaced every 12-24 months
UV lamp₹289 – ₹1195₹199 – ₹800Typically replaced every 12-18 months
Post-carbon filter₹299 – ₹800₹299- ₹800Typically replaced every 6-12 months
Service charges₹500 – ₹1,500 per visit₹500 – ₹1,000 per visitDepends on service provider and issue
Total Annual Cost₹2,800 – ₹8,000₹2,600 – ₹6,700Varies depending on water quality, usage, and specific model


Under sink purifiers involve a higher initial investment but lower long-term filter costs similar to countertop RO models.

Typical under sink RO systems cost ₹10,000-₹20,000 for the unit itself. Professional installation fees add another ₹1500+. Under sink filter replacements run ₹2,800-₹ each and are needed annually.

In contrast, countertop purifier units range from ₹3000-₹10,000 in initial purchase price. No installation is required. Their replacement filters only cost ₹500-₹1500 apiece, though these tend to need changing more frequently every 6-8 months.

SystemInitial CostInstallationFilter CostFrequency
Under Sink₹10,000-₹20,000₹2000-₹5000₹2,800-₹8,000Annual
Countertop₹5000-₹25,000None₹2,500-₹6,0006-8 months

While under sink systems require higher startup costs, their filter replacement costs are similar to normal RO.

Types of Filtrations

Under sink reverse osmosis systems combine multi-stage filtration using sediment pre-filters, RO membranes, and activated carbon post-filters. This removes up to 99% of over 1000 contaminants including chemicals, heavy metals, microbes, and dissolved mineral salts.

Countertop purifiers primarily employ single stage filtration with activated carbon block cartridges for basic particulate and chlorine removal. Some add UV light disinfection which inactivates microorganisms. They remove around 99% of common contaminants like dirt, rust, and microbes.

SystemFiltration MethodContaminants RemovedRemoval Rate
Under SinkMulti-stage (RO, carbon, sediment)1000+ (chemicals, metals, microbes, salts)Up to 99%
CountertopMulti-stage stage (RO+ carbon, some UV)Particulates, chlorine, microbesUp to 99%

Under sink reverse osmosis filtration offers superior contaminant removal over the basic single stage filters used in countertop models.


Under sink and normal water purifiers both improve water quality and safety with filtration, but have major differences when it comes to installation, capacity, maintenance and cost.

Under sink purifiers are ideal if counter space is limited and you want advanced reverse osmosis filtration, despite the higher upfront cost.

Normal purifiers suit those looking for an affordable, easy to maintain option with flexible placement, though filtration is more basic.

Consider your specific needs, budget and kitchen setup to decide between under sink or normal water purification. Reliable clean water on demand is worth the investment in either system.

Debolina Roy
Debolina Roy

Debolina Roy is our senior home improvement writer, specialising in reviewing the latest home and kitchen appliances. Debolina has written about hundreds of products like Washing Machine, refrigerator, Air conditioner, Vacuum Cleaner, Air Purifier and is committed to finding the most reliable and best value for money buys. Debolina is also interested in Tech and has completed B.Tech in Electronic and Telecommunication from Dibrugarh University. Debolina helps to uncover the washing and clean hacks too, with a focus on easy, natural solutions. Debolina also holds an MA in Journalism and has previously worked as a freelance smartphone and gaming console’s journalist, working for TechRadar, and more.

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