Shidotaira Onsen (Matsu-no-yu)
Analysis UnverifiedMatsu-no-yu is one of the sources of Shidotaira Onsen, where steam rises along the Toyosawa River; it is pumped from a drilled well at 181 liters per minute. Clear and free of taste or scent, it is an honest, unfussy water, yet it carries the softness of weak alkalinity and the warmth of sulfate and chloride. It suits bathers who prefer a gentle, easygoing spring that warms them quietly.
The bar length shows how abundant each component is compared to thresholds that make it "distinctive" (therapeutic spring standards, beauty spring criteria, etc.).
A trace component with gentle antibacterial and anti-inflammatory action.
Scores are calculated from mineral analysis data based on the Mineral Spring Analysis Guidelines (Ministry of Environment, Japan). They are unrelated to facility atmosphere or service quality.
▸Note
The temperature, pH and component values shown here are based on the hot spring analysis (source). Actual values in the bath may differ depending on heating, dilution, recycling and filtration. Please check current usage status at the facility.
At pH 8.3 this weakly alkaline water is mild, ideal for an unhurried 15 to 20 minute soak at a comfortable temperature. It warms you well, so rest until you stop sweating and rehydrate afterward.
Rich in sulfate at 388 mg/kg, this water is traditionally associated with easing stiff muscles and joints and may help relieve pain. Chloride at 151 mg/kg adds a restorative warmth that lingers after bathing.
Avoid bathing when unwell or after drinking, and hydrate often during long soaks. If your skin feels dry afterward, moisturize.
※ See the analysis data below for detailed contraindications
ANALYSIS DATAView all analysis fields ▼
Source Info
- Source name
- Shidotaira Onsen (Matsu-no-yu)
- Spring type
- Sodium Sulfate and Chloride Spring
- Source temperature
- 62.6℃
- pH
- 8.3
- Flow rate
- 181 L/min
- Flow type
- 動力揚湯
- Osmotic pressure
- 低張性
Analysis Document
- Analysis date
- 2025-06-19
- Analyst organization
- 株式会社大東環境科学
- Registration No.
- 岩手県第4号
Cations
- Hydrogen ion H⁺
- < 0.1 mg/kg
- Lithium ion Li⁺
- 0.50 mg/kg
- Sodium ion Na⁺
- 247 mg/kg
- Potassium ion K⁺
- 9.5 mg/kg
- Ammonium ion NH₄⁺
- 0.10 mg/kg
- Calcium ion Ca²⁺
- 45.9 mg/kg
- Zinc ion Zn²⁺
- 0.40 mg/kg
- Strontium ion Sr²⁺
- 0.50 mg/kg
- Total cations
- 0.30 mg/kg
Anions
- Fluoride ion F⁻
- 6.6 mg/kg
- Chloride ion Cl⁻
- 151 mg/kg
- Hydrogen sulfide ion HS⁻
- < 0.1 mg/kg
- Thiosulfate ion S₂O₃²⁻
- < 0.1 mg/kg
- Sulfate ion SO₄²⁻
- 388 mg/kg
- Bicarbonate ion HCO₃⁻
- 58.0 mg/kg
- Bromide ion Br⁻
- 0.30 mg/kg
- Iodide ion I⁻
- < 0.1 mg/kg
- Total anions
- 0.60 mg/kg
Undissociated Components
- Arsenious acid HAsO₂
- 0.50 mg/kg
- Metasilicic acid H₂SiO₃
- 91.7 mg/kg
- Metaboric acid HBO₂
- 13.9 mg/kg
- Total undissociated
- 0.11 mg/kg
Dissolved Gas
- Free carbon dioxide CO₂
- 4.4 mg/kg
- Free hydrogen sulfide H₂S
- < 0.1 mg/kg
- Total dissolved gas
- 0.00 mg/kg
Totals
- Total dissolved substances
- 1.0 mg/kg
- Component total
- 1.0 mg/kg
- Evaporation residue
- 0.98 mg/kg
Usage
- Usage status
- Unknown
Indications & Contraindications
- Bathing indications
- Cuts and grazes, Peripheral circulatory failure, Poor circulation, Depression, Xeroderma
- General indications
- High blood pressure (mild), Rheumatoid arthritis, Autonomic instability, Insomnia, Chronic pain or stiffness in muscles and joints, Muscle stiffness due to motor paralysis, Gastrointestinal dysfunction
- Contraindications
- Acute illness (especially with fever), Active tuberculosis, Malignant tumors, Severe heart disease, Respiratory failure, Renal failure, Bleeding disorders, Severe anemia, Any actively progressing illness, Pregnancy (especially early and late stages)
Drinking
- Drinkability
- Not drinkable
