The short answer: Borewell water is usually harder on hair. Municipal supply is treated and lower in dissolved minerals, so its main hair issue is chlorine and a slightly alkaline pH. Borewell water is untreated groundwater loaded with calcium and magnesium, and those minerals bind to the hair shaft wash after wash, driving dryness and breakage. A chelating shampoo like deSal lifts that bound mineral off and rinses it away, at an acidic pH.
Two houses on the same street can have completely different water. Here is how to tell which problem you actually have, and what genuinely fixes it.
Municipal water: low minerals, chlorine is the catch
Piped municipal supply (city corporation water, drawn from a river or reservoir and treated) is usually in the softer bands, often 60 to 150 mg/L hardness as CaCO3, which the WHO classifies as soft to moderately hard. The mineral load is not the headline here.
The catch is chlorine and pH. Municipal water is chlorinated for safety and tends to sit alkaline at pH 7 to 8. Your hair and scalp want acidic, roughly 4.5 to 5.5. Every wash nudges the cuticle open a little, and repeated chlorine exposure oxidises the lipid coat on the shaft. The result is dullness, tangling and a scalp that dries then overproduces oil. Real, but slower and gentler than mineral damage.
Borewell water: hardness that compounds
Borewell and tanker water is untreated groundwater. It sits in rock for years dissolving calcium and magnesium, so hardness routinely lands in the very hard band, 180 mg/L and well above. In many Indian city fringes, CGWB groundwater data shows borewell TDS running several hundred to well over a thousand ppm.
That mineral load is the real problem for hair. When hard water dries off the shaft, the calcium and magnesium do not leave with it. They deposit, layer on layer, and form a rigid film that seals moisture out and makes the fibre snap mid-length. A study measuring hair breaking strength found it dropped to about 234 units in hard water versus about 255 in soft (PMC6028999, P=0.001). Notably, a separate study at a lower hardness near 212 ppm found no significant difference (PMC3927171), which tells you the damage scales with how hard the water actually is. High-TDS borewell water is squarely in the range that does harm.
How to tell which one you have
You do not need a lab. A basic TDS meter (around ₹500 to ₹800) fills the gap in seconds: rinse a glass straight from the shower and read it. Under 150 ppm points to treated municipal supply; above 300 ppm points to borewell or tanker water; in between usually means the two are being blended, which is common when city supply runs short in summer or the monsoon delivery stutters.
The tap tells you too. Heavy white scale on the shower head and tiles, a faint earthy smell, orange staining from iron: that is borewell. Clear and odourless with a whiff of chlorine: that is municipal. Same building can flip between the two by season, so if your hair goes bad every summer and settles by August, your source is shifting.
Fixing each source
Because the two sources damage hair by different routes, each needs its own remedy. For municipal water where chlorine and alkaline pH are the issue, a shower filter that cuts chlorine helps, and an acidic clarifying wash resets the cuticle. Worth being clear on what a filter does and does not do, though: it reduces chlorine and sediment, but it does not remove the calcium and magnesium hardness, so your TDS reads about the same after it and the hardness still reaches your hair. A filter that claims to condition or sequester minerals still does not lift what is already bound to the fibre from past washes.
For borewell water, the minerals are the whole problem, and they are already stuck to the shaft. That is where chelation earns its place. A chelating agent binds the calcium and magnesium on the hair and rinses it off, rather than neutralising the metal and leaving it parked inside the fibre. A plain clarifying shampoo strips oil and product but may not chelate metal ions at all, so read for a named chelator, not just "deep clean" on the front.
Where deSal fits
deSal Hard Water Defense is a chelating shampoo built for the borewell problem: Disodium EDTA and citric acid at pH 5.45, with panthenol, hyaluronic acid and argan oil to put moisture back in the same wash. It is about ₹765 for 220 ml (roughly ₹3.5 per ml). It came out of months of R&D by two IIT Roorkee engineers, bench-tested against genuinely hard water above 500 TDS rather than clean lab tap, which is the part that takes real effort. It is in-vivo tested for skin safety (Mascot Spincontrol: dermatologically tested, clinically tested, non-irritant). Chelation is established chemistry that lifts bound calcium and magnesium off and rinses it away, which is a more complete job than a filter that leaves the hardness untouched.
FAQ
Is borewell water always worse for hair than municipal water? Usually, yes, because it carries far more calcium and magnesium and those minerals bind to the shaft and cause breakage. Municipal water is treated and lower in minerals, so its damage is milder and driven by chlorine and alkaline pH, not hardness. Test your TDS to be sure, since blended supply is common.
Will a shower filter fix borewell water damage? Only partly. A filter cuts chlorine and sediment but does not remove the calcium and magnesium hardness, so your TDS reads about the same and the minerals still reach your hair. For borewell water you need something that lifts the bound minerals off the shaft, which is what a chelating shampoo does.
Which supply do I have, municipal or borewell? A ₹500 to ₹800 TDS meter answers it in seconds: under 150 ppm is likely treated municipal supply, above 300 ppm is likely borewell or tanker. White scale on the shower head, an earthy smell or iron staining also point to borewell.
Is a chelating shampoo the same as a clarifying shampoo? Not quite. Clarifying strips oil and product buildup; chelating specifically binds metal ions like calcium and magnesium and rinses them off. Many chelating shampoos clarify too, but a plain clarifying shampoo may not chelate.
Sources
- Hard water, calcium deposition and reduced hair breaking strength (about 234 vs 255, P=0.001): PMC6028999
- Lower hardness near 212 ppm showed no significant difference in breaking strength: PMC3927171
- Shampoo pH, cuticle friction and breakage: Gavazzoni Dias et al., Int J Trichology 2014, PMC4158629
- WHO drinking-water hardness bands (soft, moderate, hard, very hard): WHO hardness in drinking-water guidance
- Indian groundwater TDS and hardness by region: CGWB groundwater data
