宝の湯
Takara-no-yu Spring曹
Bicarbonate
- Color
- colorless and transparent
- Taste
- very faintly salty
- Odor
- odorless
Sodium Bicarbonate spring
Hot source · 43°CHigh silicaHigh radon
Composition fingerprint3.4 g/kg dissolved · Hypotonic
Na⁺93
HCO₃⁻80
Cl⁻20
◀ CationsAnions ▶
- Sodium Na⁺
- salt's cation — pairs with chloride to make the water salty.
- Bicarbonate HCO₃⁻
- "soda" — softens skin, leaves it smooth.
Known good for
- Smooth skindry, rough skin
- Aches & jointsstiff shoulders
- Recoveryfatigue, stress
A sodium-led bicarbonate spring — the classic 'jūsō-sen' (soda-water) style, neutral at pH 7.12. With 3,400 mg/kg of dissolved solids and a generous 90 mg/kg of metasilicic acid, it sits in the Japanese 'beauty-water' family — soft on the skin, with just the faintest salty edge on the tongue and otherwise no colour or scent. The unusual twist is a radon load of about 58 Bq/kg, putting it in the 'hormesis' tradition of radon springs as well.
Analyzed May 23, 2022·株式会社 MCエパテック 熊本分析センター