下呂温泉
Gero Onsen湯
Simple
Sodium Chloride spring
Hot source · 56°CHigh silicaTop-decile alkaline
Composition fingerprint0.4 g/kg dissolved · Hypotonic
Na⁺95
Cl⁻56
CO₃²⁻17
◀ CationsAnions ▶
- Sodium Na⁺
- salt's cation — pairs with chloride to make the water salty.
- Chloride Cl⁻
- table-salt anion — coats the skin and holds heat in.
Known good for
- Aches & jointsstiff shoulders
- Smooth skindry, rough skin
- Recoveryfatigue, stress
An alkaline simple thermal spring from the Gero supply — gentle in composition, with dissolved solids of just 374 mg/kg, so it sits light on the body rather than pressing minerals into the skin. The alkalinity gives it the slippery feel that places it squarely in Japan's beauty-water family, and close to 60 mg/kg of metasilicic acid leaves a thin silica film that makes skin feel noticeably smoother afterwards. Carbonate and fluoride stand out in an otherwise sparse ion table, lending the water a soft body unusual for a simple spring.
Analyzed Dec 3, 2018
