Have you ever stopped to taste your drinking water? If you haven't, that's the first reason to keep reading. The taste of your water is shaped by something called TDS, or Total Dissolved Solids, and it's the most important number most people in India misunderstand.
As one of the few certified water sommeliers in India, the first thing I look at when evaluating any natural mineral water is its TDS. It tells me what essential natural minerals the water is carrying, where it has come from, and whether it belongs in a daily wellness routine. In wine terms, TDS is the closest thing water has to terroir.
What does TDS actually mean?
TDS measures the minerality of your water: the essential natural minerals dissolved into it from the rock and earth it passes through. It is measured in milligrams per litre (mg/l), either with a handheld TDS meter or by evaporating water at 180°C in a lab and weighing what remains.
A note on home TDS meters: while they are widely available and useful as a basic indicator, they must be regularly calibrated against a known reference solution to give accurate readings. An uncalibrated meter can be misleading. For a truly accurate assessment, certified lab testing remains the gold standard.
When water comes from a protected confined aquifers like Aava's certified source, the geology of that source determines the mineral profile. Different aquifer, different minerals, different taste. That is the terroir of water, and it is what makes natural mineral water a meaningful part of a healthy lifestyle.
TDS classification: how to read the number
Natural mineral waters are typically classified into five TDS bands:
- Super Low: 0 to 50 mg/l
- Low: 50 to 250 mg/l
- Medium: 250 to 800 mg/l
- High: 800 to 1,500 mg/l
- Very High: 1,500 mg/l and over
Glacier and iceberg waters tend to fall in the super low band. RO-processed packaged drinking water lands here too, not because it is clean in any meaningful sense, but because the RO process strips out all essential natural minerals along with any impurities. At the other extreme, seawater registers around 25,000 mg/l, which is why it is undrinkable.
Aava water sits comfortably in the medium range, naturally balanced for daily drinking. An early WHO-commissioned assessment identified roughly 300 mg/l as an optimal level for daily drinking water, and medium-mineralisation waters remain widely recognised as the sweet spot for everyday hydration and wellness.
Why low TDS isn't as healthy as it sounds
In India, TDS has become the headline number people use to judge whether water is "safe." A high TDS reading sets off alarm bells, and a low number gets treated as proof of purity. Both reactions miss the point.
TDS on its own tells you nothing about quality. It tells you the quantity of dissolved content in your water. What matters is what that content is made of. Two waters can have the same TDS where one is rich in calcium, magnesium, and bicarbonate from a natural spring, and the other contains dissolved contaminants. Same number, completely different water.
The flip side is equally important. A near-zero TDS does not mean cleaner water. It means demineralised water. RO systems and most packaged drinking water brands strip out essential natural minerals along with impurities, leaving you with water that has been processed of its nutrition. The World Health Organisation has flagged long-term consumption of demineralised water as suboptimal, because drinking water is meant to be a meaningful source of trace minerals as part of a healthy lifestyle.
The simple way to think about it: your washing machine wants low-TDS soft water. Your body wants the opposite. That is why it is called mineral water.
What Indian regulations say about minerals in packaged water
This is no longer just nutritional opinion. Indian regulation now formally recognises that drinking water needs to deliver mineral value to the consumer.
Under FSSAI's standards for Packaged Drinking Water, the permissible TDS range is set at 75 to 500 mg/l, along with minimum levels for essential minerals including calcium and magnesium. In practical terms, this means packaged drinking water brands using reverse osmosis or similar demineralising processes are required to add essential minerals back into the water before bottling, in order to meet these minimum mineral specifications.
Natural mineral water like Aava is a separate category altogether. Aava is BIS IS 13428-certified, originating from the Aravallis, and bottled at source with no treatment that alters its original mineral composition. The minerals you drink in Aava are the same essential natural minerals that nature and geology has been producing for thousands of years, naturally present, and never removed.
For consumers, this means a meaningful choice: water where minerals are added back in a factory to meet a regulatory minimum, or water born with these minerals.
What's inside Aava's TDS
Here is what Aava's mineral profile looks like, and what each mineral contributes as part of a healthy daily routine.
Magnesium (Mg²⁺): 11.5 mg/l (average)
Magnesium plays a role in over 300 biochemical reactions in the body. It supports muscle contraction, nerve function, the activity of energy-producing enzymes, and contributes to bone health and healthy blood vessel function. Adults typically need 300 to 400 mg daily for overall wellness.
Calcium (Ca²⁺): 23 mg/l (average)
Calcium supports bone density, dental health, cell membrane stability, and the transmission of nerve and muscle signals. Adults, and premenopausal women in particular, need 800 to 1,200 mg daily. The calcium in natural mineral water is highly bioavailable, which means the body absorbs it efficiently as part of a balanced diet.
Bicarbonate (HCO₃⁻): 200 to 250 mg/l
Bicarbonate plays a key role in maintaining the body's pH balance and supports healthy digestion. It is the same compound your stomach naturally produces, and it is part of why naturally alkaline waters like Aava, with a natural pH of 8, taste smooth rather than sharp.
Silica (SiO₂): 13 mg/l
Silica contributes to collagen production, which supports hair, skin, nail, and connective tissue health, an essential part of any wellness routine. Most adults need 20 to 30 mg daily, and Aava is one of India's only naturally alkaline mineral waters with a meaningful silica content.
Sodium (Na⁺): below 100 mg/l
Natural mineral water sodium is not the same as table salt. It is unprocessed and naturally bound to bicarbonate, which means it functions very differently in the body. Aava water's natural sodium content is well below 100 mg/l, in line with a balanced healthy lifestyle.
Trace minerals like potassium, fluoride, and chloride round out the profile and contribute to overall hydration.
TDS is not the same as hardness
This is the misconception that comes up most often. People see a higher TDS number and assume the water is "hard," the kind that leaves residue on taps and damages washing machines.
Hardness is a separate measurement entirely. It depends only on calcium and magnesium content, calculated as:
(Calcium × 2.5) + (Magnesium × 4)
Water is technically hard when this number falls in the 120 to 180 mg/l range. Aava is a naturally alkaline mineral water with a pH of 8 and a hardness of just 101, which puts it firmly in the "slightly hard" category that is actually ideal for drinking. Hard water affects machines more than humans. For your washing machine, soft demineralised water works better. For your body and for a healthy lifestyle, you want essential natural minerals.
What to actually look for in your water
When you pick up a bottle of water, here is the short version:
- Check the source: natural mineral water, not packaged drinking water
- Check for BIS IS 13428 certification: the standard for natural mineral water in India
- Check the TDS: medium range is ideal for daily drinking and supports a healthy lifestyle
- Check the mineral composition: not all TDS is created equal
- Look for naturally alkaline water with a balanced pH, not artificially alkalised water
- Remember, TDS is not the same as hardness
Naturally alkaline mineral water like Aava, with a natural alkaline pH of 8, gives you what bottled water should: real hydration, essential natural minerals, and a taste that comes from the source rather than a processing line.
Frequently Asked Questions
What is the ideal TDS for drinking water in India?
A medium TDS, roughly 250 to 500 mg/l, is widely considered the most suitable range for daily consumption. Aava sits comfortably within this range, naturally balanced and aligned with a healthy wellness routine.
Is high TDS water bad for you?
Very high TDS water (above 1,500 mg/l) is not recommended for daily drinking, and seawater at 25,000 mg/l is undrinkable. But a higher TDS does not automatically mean unsafe. It depends on which essential natural minerals make up that TDS.
Can RO water be too low in TDS?
Yes. RO water typically falls into the super low TDS category because the process removes minerals along with impurities. The World Health Organisation has flagged long-term consumption of demineralised water as suboptimal, since drinking water is meant to contribute to your daily mineral intake.
Does FSSAI require packaged water to contain minerals?
Yes. FSSAI's standards for Packaged Drinking Water specify a permissible TDS range of 75 to 500 mg/l, along with minimum levels for essential minerals like calcium and magnesium. Packaged drinking water brands using RO or similar demineralising processes are therefore required to add essential minerals back before bottling to meet these specifications. Natural mineral water like Aava sits in a separate category, BIS IS 13428-certified and originating from the Aravalli Hills with all its minerals naturally present at source.
How do I check the TDS of my water at home?
A handheld TDS meter, available online for ₹300 to ₹1,000, gives you a reading in seconds. However, TDS meters must be regularly calibrated against a known reference solution to deliver accurate readings, so an uncalibrated meter can be misleading. For a definitive reading, a certified lab test remains the most reliable option.
What is the TDS of Aava Natural Mineral Water?
Aava is a naturally alkaline mineral water with a balanced TDS that sits in the medium minerality category, ideal for daily drinking and a healthy lifestyle.
Is TDS the same as water hardness?
No. Hardness is calculated only from calcium and magnesium content. A water can have a moderate TDS but still be soft, or a low TDS but technically hard. Aava is a naturally alkaline mineral water with a natural pH of 8, only slightly hard, and ideal for daily drinking.
