Best Under Sink Water Purifier in India, as per Reddit (2026)

Ask Reddit for the best under sink water purifier in India and you will not get one model name back. You get the same four pieces of advice in almost every thread: test your water’s TDS before you choose RO, measure the cabinet before you buy, insist on a proper steel faucet, and pick the company whose technician will actually turn up in year two. Get those right and most under sink purifiers will serve you well; get them wrong and the best spec sheet will not save you.

How We Read the Threads

We went through roughly 60 threads from 2023 to 2026 on r/india, r/IndianHomeImprovement, r/bangalore, r/mumbai, r/pune, r/hyderabad and r/gurgaon where someone asked about an under sink, under counter or “hidden” RO for a modular kitchen. We ignored posts that were plainly promotional, grouped the rest by theme, and counted which advice came up again and again.

We have left brand names out on purpose. Reddit’s opinions on individual brands swing with whoever had a bad technician visit last month, and they rarely survive a second thread. The patterns below are more stable, and more useful, than any single brand verdict.

Rule One: Check Your TDS Before Anything Else

The single most repeated reply on Reddit is some version of “buy a TDS meter first”. It is good advice. Whether you need RO at all depends on what is coming out of your tap.

• Low TDS municipal water (roughly under 200 to 300 mg/L) is often fine with a UF or UV purifier that keeps minerals in. Our explainer on whether you need RO if your TDS is below 200 covers the grey areas.
• Borewell, tanker or mixed supply usually means higher and changing TDS, and RO earns its place. The BIS IS 10500 acceptable limit is 500 mg/L, with 2000 mg/L permissible only where there is no alternative source.
• Supply that changes with the season is common in Bengaluru, Gurugram and Chennai. Threads from people whose water switched between corporation and tanker supply almost always end with “get RO, it handles both”.

If you do not want to buy a meter, start with our TDS lookup by city and pincode to see what your area typically gets.

The Cabinet Problem Nobody Mentions in the Showroom

Under sink purifiers live in the most crowded cupboard in an Indian kitchen. Reddit is full of people who found that out after delivery.

The cabinet issues that come up most:

• No power socket under the sink. RO needs electricity. If your kitchen is still being built, ask for a socket inside the sink cabinet now; adding one later means chasing a wire through finished tiles.
• Not enough room. The purifier, its storage tank, the inlet line and the reject line all compete with the drain trap, the dustbin and cleaning supplies. Measure the clear width, depth and height, and subtract the space the sink bowl and trap take up.
• Reject water. RO sends some water to drain. Several threads suggested routing it to a bucket or can for mopping and plants rather than straight down the drain; our guide on reusing RO reject water covers what it is good for.
• Leaks you cannot see. A drip under the counter can soak the cabinet base for weeks before anyone notices. Redditors recommend checking the fittings with a torch for the first few days after installation, and every few months after that.

None of this is a reason to avoid under sink purifiers; it is the honest list of under sink disadvantages you plan around. Our complete under sink RO guide has the cabinet measurements in detail.

The Faucet and the Granite Hole

The faucet is the only part of an under sink purifier you see and touch every day, and Reddit has strong feelings about it.

• Material. A stainless-steel faucet that sits firmly on the counter is the most common request. A loose or plastic faucet is the most common complaint.
• The hole. The faucet needs a hole in the counter or sink deck. Drilling granite or quartz is routine for a good installer and risky for a bad one. Ask who drills, with what, and whether they have done your counter material before.
• Position. Put the faucet where a tall bottle or a steel pot fits under it, not squeezed against the backsplash.

Service Beats Spec Sheets

If Reddit agrees on anything about water purifiers, it is that the company behind the purifier matters more than the purifier. Most of the angriest threads are not about water quality at all. They are about technicians who did not show up, filters that cost far more than expected, and annual plans pushed hard at every visit.

The questions Redditors tell each other to ask before buying:

• Who installs it: the company’s own team, or a third-party contractor?
• What do replacement filters and the membrane cost, and how often will they be needed for my water?
• What does the warranty cover, and for how long?
• Is there an annual plan, and is it optional? Our guide on whether a water purifier AMC is worth it walks through the maths.

Where Reddit Gets It Wrong

Reddit’s instincts on purifiers are mostly sound, but a few repeated claims need a correction.

• “Just get a local assembled RO, it’s the same thing.” Sometimes it is a reasonable choice, especially if you have a technician you trust. But build quality, fittings and after-sales support vary enormously, and nobody is accountable when a fitting leaks into your cabinet. Our comparison of assembled RO vs branded purifiers covers the trade-off honestly.
• “RO water is unhealthy because it removes minerals.” RO does remove most dissolved minerals, and some people prefer the taste of water with more of them. But most of your minerals come from food, not drinking water, and a well-designed purifier can add minerals back for taste. It is a taste and preference question, not a reason to drink high-TDS water.
• “Boiling is enough.” Boiling inactivates most microbes. It does nothing to dissolved salts or chemicals, which is the main reason people in high-TDS areas buy RO in the first place.
• “Under sink means more wastage.” Placement does not change how much water an RO rejects. Membrane design, input TDS and how the system is set up do.

Reddit’s Under Sink Checklist

Boiled down, the advice from the threads gives you a simple checklist:

1. Test your TDS, or look it up. RO for high or changing TDS; UF or UV for low, stable municipal water.
2. Measure the cabinet and confirm there is a power socket inside it.
3. Decide where the reject water goes: drain, bucket or storage can.
4. Insist on a sturdy stainless-steel faucet and a confident installer for the counter hole.
5. Ask who installs and services it, and what filters cost.
6. Check the leak points in the first week and every few months after.
7. Re-test the output water now and then, so you know when filters are due rather than guessing.

How Boon Tap Answers the Checklist

Boon Tap is Boon’s under sink purifier: the unit sits in the cabinet and a dedicated faucet sits on the counter. Here is how it lines up against the Reddit checklist, including where it is not the right pick.

Reddit’s concern	How Boon Tap handles it
Test TDS first	UltraOsmosis RO rated for input up to 2000 TDS. For low-TDS supply, Boon Tap UF skips RO altogether.
Re-test the output	WaterAI monitors input and output TDS and filter health, so you are not relying on a handheld meter.
Reject water	Boon’s installers can route the reject pipe to a bucket or storage can on request.
Who installs it	Free installation by Boon’s own team, not a contractor.
Warranty and risk	2-year warranty and a 10-day money-back guarantee.
Storage	8-litre tank under the counter.

Boon Tap is from ₹23,500 at the time of writing. Boon was founded in 2013 by ex-IIT Kanpur engineers, and its systems run in more than 4,000 organisations and 400+ hotels, so it is not a new name in water, even if it is newer on Reddit.

Where it is not the right pick: if your TDS is low and stable, you do not need RO, so look at Boon Tap UF instead. If your sink cabinet has no room or no plug point and you cannot add one, a wall-mounted purifier is the easier route. And if your budget is closer to a basic assembled RO, Tap is a premium product and priced like one.

Frequently Asked Questions

Which is the best under sink water purifier in India according to Reddit?

Reddit rarely agrees on a single model. The consistent advice is to check your water’s TDS first, choose RO only if your TDS is high or changes with the season, measure your sink cabinet and confirm it has a power socket, insist on a sturdy steel faucet, and choose a company whose own team installs and services the purifier. Brand opinions on Reddit change quickly; those principles do not.

Is an under sink water purifier worth it in India?

It is worth it if you have a modular kitchen with space and a power socket under the sink, and you want a clear counter and wall. The water quality is the same as a good wall-mounted purifier; the benefit is the cleaner kitchen. If the cabinet is cramped or you rent and move often, a wall-mounted purifier is usually simpler to install and to take with you.

Do under sink purifiers need electricity?

Under sink RO purifiers need electricity, because the RO pump and UV run on power. That is why Reddit threads keep warning people to ask for a plug point inside the sink cabinet before the kitchen is finished. A non-electric UF purifier can work without power, but it does not reduce TDS, so it only suits water that is already low in dissolved salts.

Can I install an under sink water purifier myself?

It is possible if you are confident with plumbing, but most people are better off with a professional installer. The job involves tapping into the water line, connecting the drain for reject water, drilling a hole in the counter or sink deck for the faucet, and checking every fitting for leaks. A mistake under the counter can go unnoticed for weeks and damage the cabinet.

Does an under sink RO waste more water than a wall-mounted RO?

No. Where the purifier sits does not change how much water it rejects. Reject water depends on the membrane, your input TDS and how the system is set up. What under sink placement does change is where that water can go: many people route it to a bucket or can in the cabinet and reuse it for mopping, cleaning or plants.

What TDS level means I need an RO purifier?

BIS IS 10500 sets 500 mg/L as the acceptable limit for drinking water, with up to 2000 mg/L permissible only where no alternative exists. Above about 300 to 500 mg/L, or if your supply switches between municipal water, borewell and tankers, RO is usually the right choice. Below about 200 mg/L from a treated municipal supply, a UF or UV purifier is often enough.