Introduction: Why Knowing Your Water’s TDS Matters
If you're using an RO water purifier or even just curious about the water you drink every day, you've likely come across the term TDS, or Total Dissolved Solids. While many understand that TDS relates to water quality, few truly know what the minimum TDS for drinking water in India should be.
This article breaks it down in simple terms—so you’ll know what TDS is, what level is considered safe, and how to ensure you’re drinking water that supports your health rather than harming it. Let’s get started.
What Is TDS in Drinking Water?
TDS (Total Dissolved Solids) measures the amount of organic and inorganic substances—like salts, minerals, and metals—dissolved in water. It's expressed in milligrams per liter (mg/L) or parts per million (ppm).
Common elements that contribute to TDS include:
Some of these are beneficial, while others, especially at higher concentrations, can be harmful.
Is There a Minimum TDS for Drinking Water in India?
According to the Bureau of Indian Standards (BIS) under IS 10500:2012:
Important: BIS does not define a strict minimum TDS value, but water with TDS below 50 ppm is generally not recommended for regular consumption due to lack of essential minerals.
While ultra-purified water (like distilled water) has a TDS close to zero, it lacks vital minerals such as calcium and magnesium, which are essential for human health.
Safe TDS for Drinking Water: What’s Ideal?
Here’s a breakdown of TDS levels and their implications:
| TDS Level (ppm) |
Water Quality |
| 0–50 |
Very low – lacks minerals |
| 50–150 |
Excellent |
| 150–300 |
Good |
| 300–500 |
Acceptable |
| 500–1200 |
Poor – high in salts |
| 1200+ |
Unsafe for drinking |
So, What’s the Minimum TDS You Should Aim For?
Most water experts recommend a TDS level between 75–150 ppm for:
Water with TDS below 50 ppm may taste flat and fail to support mineral needs in your diet. This is particularly important if you're using RO water purifiers, which can drastically reduce TDS.
TDS Level for RO Water: How Low Is Too Low?
RO (Reverse Osmosis) purifiers are extremely effective at removing dissolved impurities, especially:
However, they can also remove beneficial minerals. Without regulation, an RO system can drop TDS to below 30 ppm, which is not ideal.
Ideal TDS for RO Water:
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Minimum TDS: 75 ppm
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Maximum TDS: 150 ppm
To achieve this, many RO systems come with a TDS controller, which balances purified water with a portion of raw water to retain minerals.
Role of TDS Controller in Water Purifier
A TDS controller in a water purifier helps regulate the final output TDS after purification. It mixes a portion of unfiltered water (rich in minerals) with RO-purified water, achieving a balanced TDS.
Benefits of TDS Controller:
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Restores essential minerals
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Improves taste of water
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Prevents over-purification
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Keeps TDS in the optimal range for health
If your RO unit does not have a TDS controller or mineralizer, your water may become too soft, lacking in calcium, magnesium, and potassium—especially problematic for children and elderly people.
How to Measure TDS at Home
Measuring TDS is simple and affordable. Here’s how:
1. Digital TDS Meter
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Costs ₹200–₹500 online or at appliance stores
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Dip the meter into a glass of water, and it instantly shows the TDS in ppm
2. In-Built RO TDS Display
3. Water Testing Services
Health Risks of Drinking Water with Very Low TDS
While high TDS levels are known to cause health problems, extremely low TDS can also have side effects:
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De-mineralization: Lack of calcium, magnesium, and potassium
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Poor bone health: Long-term consumption may affect bone density
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Flat taste: Water may taste unnatural or unappealing
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Electrolyte imbalance: Can disrupt natural mineral balance in your body
This is why completely demineralized RO water without TDS regulation is discouraged.
Common Sources of Drinking Water in India and Their TDS
| Water Source |
Typical TDS Range (ppm) |
Notes |
| Municipal Tap Water |
200–500 |
May vary by region |
| Borewell Water |
300–1500 |
Often contains excess salts/metals |
| River/Lake Water |
100–300 |
Needs filtration but low TDS |
| Tanker Water |
300–900 |
Varies; check TDS regularly |
| RO Purified Water |
20–120 (can be adjusted) |
Use a TDS controller for balance |
Tips to Maintain Safe TDS in Your Drinking Water
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Install an RO system with TDS control
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Check TDS every 3–6 months, especially if you're using borewell or tanker water
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Avoid ultra-low TDS—use a mineralizer or alkaline filter if needed
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Change RO filters regularly to ensure consistent TDS regulation
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Consult BIS standards to verify overall water safety beyond just TDS
FAQs: Minimum TDS for Drinking Water in India
Q1. Is there a minimum TDS for drinking water according to BIS?
Answer: BIS does not specify a strict minimum TDS, but the desirable TDS limit is 500 ppm. Water below 50 ppm may lack essential minerals and is not ideal.
Q2. Can I drink RO water with 20 ppm TDS?
Answer: Technically yes, but it's not recommended. That level lacks beneficial minerals. Use a TDS controller or mineralizer to increase TDS to 75–150 ppm.
Q3. What is a safe TDS level for drinking water in India?
Answer: A safe range is between 75 to 300 ppm. This ensures safety, taste, and mineral presence.
Q4. How do I know if my water’s TDS is too low?
Answer: Signs include a flat taste and dry mouth feel. Use a digital TDS meter to confirm. If below 50 ppm, it's too low for regular drinking.
Q5. What happens if TDS is too high?
Answer: Water with high TDS (above 500 ppm) may contain harmful contaminants like nitrates, fluorides, or heavy metals. It also causes scale buildup in appliances.
Conclusion: Keep Your TDS Balanced for Better Health
TDS is not just a number—it’s a reflection of your water’s overall safety and quality. In India, there’s no official minimum TDS, but experts agree that water with TDS below 50 ppm is not ideal for daily consumption.
The optimal range for drinking water is between 75–150 ppm, especially if you’re using an RO water purifier. With a TDS controller in your water purifier, you can strike the right balance between purity and nutrition.
If you haven't tested your water’s TDS yet, now is the time. A simple digital meter or your RO purifier’s display can help you ensure your family is drinking water that’s not just clean—but truly healthy, For more read out our blog on Minimum TDS For Drinking Water.
