乙丸温泉
Otomaru OnsenOperated by · 由布市
湯
Simple
- Color
- colorless and clear
- Taste
- almost tasteless
- Odor
- odorless
Sodium Chloride-Bicarbonate spring
pH 8.3Weakly alkalineHot source · 58°CHigh silica
Composition fingerprint0.6 g/kg dissolved · Hypotonic
Na⁺73
Cl⁻35
HCO₃⁻29
SO₄²⁻18
◀ 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
A simple thermal spring — gentle, lightly mineralized water with nothing sharp about it. It is weakly alkaline and soft on the skin, and at 0.59 g/kg of dissolved solids it sits on the light side of the mineralization scale. What lifts it out of the ordinary is the silica: 172 mg/kg of metasilicic acid puts this water squarely in Japan's beauty-water family, leaving the kind of thin, moisturizing film that makes skin feel noticeably smoother once you are out of the bath.
Sampled at wellhead·Analyzed Feb 15, 2023·公益社団法人大分県薬剤師会 検査センター·Cert no. 大薬検 第7R-23020007号