Sukayu Onsen (Yonbu Robu no Yu)
Analysis UnverifiedThis spring rises at the spa retreat on the northwest flank of the Hakkoda Mountains that became Japan's first National Health Resort Hot Spring, and it is the densest and most acidic of the local springs. Its name, meaning "four parts, six parts," is said to come from long local usage. The heavy mineral load gives it a firm tingle on the skin and heat that reaches the core; comparing it with the other springs and finding the soak that suits you is the pleasure of a healing retreat.
The bar length shows how abundant each component is compared to thresholds that make it "distinctive" (therapeutic spring standards, beauty spring criteria, etc.).
Strong astringent action that tightens skin. A key component of acidic springs, suited to oily or acne-prone skin.
An iron-rich spring whose water turns yellow-brown to red-brown when exposed to air. Strong heat retention.
A natural moisturizer also used in skincare lotions. Forms a thin veil on the skin to reduce moisture loss after bathing.
Mild antibacterial action keeps the skin clean. Trace transdermal absorption supports tooth and bone health.
Oxidized iron. Tints the water reddish-brown, lending a visually dramatic, "powerful" bath feel.
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.
With dense minerals and strong acidity, repeat short soaks, rinse lightly with fresh water afterward, and keep the water out of your eyes.
With strong acidity from 25.2 mg/kg of hydrogen ions and rich chloride and sulfate, the water offers restorative warmth and has long been valued for balneotherapy at this healing retreat.
Strongly acidic and mineral-dense: those with sensitive skin should avoid long soaks and rinse with fresh water afterward.
※ See the analysis data below for detailed contraindications
ANALYSIS DATAView all analysis fields ▼
Source Info
- Source name
- Sukayu Onsen (Yonbu Robu no Yu)
- Spring type
- Acidic Iron(II,III)-containing Aluminum Sulfate and Chloride Spring
- Source temperature
- 67.1℃
- pH
- 1.53
Analysis Document
- Analysis date
- 2022-10-18
- Analyst organization
- 一般財団法人 青森県薬剤師会 食と水の検査センター
- Registration No.
- 青森県第2号
Cations
- Hydrogen ion H⁺
- 25.2 mg/kg
- Lithium ion Li⁺
- 0.00 mg/kg
- Sodium ion Na⁺
- 71.7 mg/kg
- Potassium ion K⁺
- 27.4 mg/kg
- Ammonium ion NH₄⁺
- 0.40 mg/kg
- Magnesium ion Mg²⁺
- 77.3 mg/kg
- Calcium ion Ca²⁺
- 286 mg/kg
- Aluminum ion Al³⁺
- 326 mg/kg
- Manganese ion Mn²⁺
- 3.0 mg/kg
- Iron(II) ion Fe²⁺
- 78.2 mg/kg
- Iron(III) ion Fe³⁺
- 41.7 mg/kg
- Zinc ion Zn²⁺
- 0.30 mg/kg
- Lead ion Pb²⁺
- < 0.01 mg/kg
- Copper ion Cu²⁺
- < 0.01 mg/kg
- Cadmium ion Cd²⁺
- < 0.005 mg/kg
- Total cations
- 0.94 mg/kg
Anions
- Fluoride ion F⁻
- 10.2 mg/kg
- Chloride ion Cl⁻
- 789 mg/kg
- Hydrogen sulfide ion HS⁻
- 0.00 mg/kg
- Thiosulfate ion S₂O₃²⁻
- 0.20 mg/kg
- Sulfate ion SO₄²⁻
- 2312 mg/kg
- Bicarbonate ion HCO₃⁻
- 0.00 mg/kg
- Carbonate ion CO₃²⁻
- 0.00 mg/kg
- Bromide ion Br⁻
- 0.00 mg/kg
- Iodide ion I⁻
- 0.00 mg/kg
- Hydrogen sulfate HSO₄⁻
- 1957 mg/kg
- Sulfide ion S²⁻
- 0.00 mg/kg
- Total anions
- 5.1 mg/kg
Undissociated Components
- Sulfuric acid H₂SO₄
- 124 mg/kg
- Arsenious acid HAsO₂
- 1.7 mg/kg
- Metasilicic acid H₂SiO₃
- 312 mg/kg
- Metaboric acid HBO₂
- 6.6 mg/kg
- Total undissociated
- 0.44 mg/kg
Dissolved Gas
- Free carbon dioxide CO₂
- 32.9 mg/kg
- Free hydrogen sulfide H₂S
- 0.00 mg/kg
- Total dissolved gas
- 0.03 mg/kg
Totals
- Total dissolved substances
- 6.5 mg/kg
- Component total
- 6.5 mg/kg
Usage
- Heating
- No
- Dilution
- No
- Recycle / Filter
- No
- Additives
- No
- Disinfection
- No
Indications & Contraindications
- Bathing indications
- Atopic dermatitis, Plaque psoriasis, Epidermal suppuration, Impaired glucose tolerance (diabetes), 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), Sensitive skin or mucous membranes, eye conditions (acidic springs)
Drinking
- Drinkability
- Not drinkable
