What is the TDS? Water Scientist Dr Anil Kumar explains why Indians must ask these water quality questions and beyond

Learn seven essential questions to ask about water quality in India beyond TDS to ensure safe drinking water and make informed choices for your household.

How much TDS is good in water in India? How to reduce TDS in water at home? (Getty Images/iStockphoto)

By Tavishi Dogra

Tavishi Dogra is a Deputy Chief Content Producer, Health & Wellness, at Hindustan Times. She has over 9 years of experience writing about fitness, nutrition, and mental well-being, translating medical research and expert insights into practical advice readers can trust.

Career journey and experience
Tavishi began her health journalism journey in 2017, and has since reported for RSTV, Financial Express, Jagran, HT Media Labs and Zee. She joined Hindustan Times to simplify wellness subjects by cutting through jargon.

From decoding health trends and interviewing doctors to testing fitness routines herself, Tavishi always approaches content with one filter: “Will this help someone make a better decision today?”

Subject expertise
With 9+ years tracking India’s health conversations, Tavishi knows the gap between clinical advice and daily life. She knows fads from fundamentals and curates science-backed, expert-recommended solutions.

In fitness, she breaks down bodyweight training, recovery, and posture fixes for desk-bound readers. In nutrition, she translates guidelines into affordable, desi meal tweaks. In mental well-being, she focuses on stigma-free, actionable tools — all backed by research, expert input, and lived context.

Education and professional background
Tavishi holds a Master’s degree in Journalism and Mass Communication and began her career reporting on public affairs for broadcast. Those early years in policy and TV shaped how she writes today: fast, factual, and human-first.

Editorial Philosophy
I write with one single goal: To simplify health in a world full of noise by finding what’s actually doable, safe, and evidence-based for my readers. I test claims against research and user experiences. When all else fails, I speak to the expert who sees 50 patients a day, not the one with the most followers.

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For many Indian households, checking the TDS level has become almost as routine as checking the price of a water purifier. But TDS is only one part of the picture. The CGWB’s 2024 groundwater assessment found nitrate levels above the BIS permissible limit in nearly 20% of monitored samples, while fluoride exceeded the limit in 9.04% and arsenic in 3.35%. These numbers show why a single reading on a TDS meter may not tell the full story of the water flowing into your home.

7 water quality questions Indians should be asking

So, the next time you check your water quality, Dr Anil Kumar, Chief Water Scientist, Eureka Forbes, shares seven questions worth asking:

1. Is the water actually safe to drink, even if the TDS looks fine?

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A reassuring TDS number doesn't automatically mean the water is free of bacteria. Ask whether the water has been tested for E. coli and coliform bacteria, particularly if your home depends on groundwater, tankers, or other variable sources. These are among the parameters covered under India’s drinking-water standards.

2. What is actually contributing to my TDS?

Two water samples can have a similar TDS reading but contain very different dissolved substances. This is why it can be useful to know whether your water contains concerns such as fluoride, nitrate, or arsenic, rather than treating the TDS number as a complete quality check.

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3. Could my everyday water contain heavy metals?

For households in older buildings or areas with particular groundwater concerns, it is worth asking about contaminants such as lead, cadmium, mercury and chromium. A TDS meter cannot tell you which individual substances are present in the water.

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4. Does my water change with the season?

The water you use in summer may not necessarily have the same quality during or after the monsoon. Changes in groundwater, rainfall, and contamination pathways can affect water quality, so periodic testing is a sensible practice rather than relying on a single reading taken months ago.

5. Am I choosing a purifier based on my water, or just its TDS claim?

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Instead of asking whether a purifier can “reduce TDS”, understand what your household water actually needs. RO, UV, UF, activated carbon, and membrane-based technologies serve different purposes, so the right choice depends on the water source and its quality.

6. What else does the filtration system target?

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For consumers looking beyond conventional dissolved salts, filtration technology and independently verified removal claims deserve attention. Newer approaches, such as Purification with nanopore filter technology, show that purification is increasingly moving toward addressing a wider range of contaminants rather than making TDS reduction the sole measure of performance.

7. When was the last time the purifier was serviced?

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Even a sophisticated purifier needs attention. Check filter life, replacement schedules, and maintenance requirements rather than assuming that its performance remains unchanged indefinitely. For something used every day, upkeep is part of water hygiene too.

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