水神の湯
Suijin no YuSodium-Magnesium Bicarbonate spring
An iron(II)-bearing sodium-magnesium bicarbonate spring that oxidizes reddish-brown on contact with air. The 48.4 °C source is delivered to the bath cooled to about 42 °C; the bicarbonate character also leaves skin feeling smooth. Iron measures 20.2 mg/kg — at the iron-spring threshold — with a generous 989 mg/kg of free CO₂.
- Iron-rich
Analyzed Jul 25, 2007·Cert no. 大分県衛生第3号