Deyu Onsen Doshun-no-Iwaya (Well No. 2, Outer Casing)
Analysis UnverifiedDeyu Onsen, said to have been opened by Kobo Daishi some 1,200 years ago, is regarded as Niigata's oldest spa and forms the Gozu hot spring area with Murasugi and Imaita. Seiko-kan has over 300 years of history, and its three-story wooden building from 1928 is a Registered Tangible Cultural Property. The low-temperature spring of about 30°C flows naturally in modest volume, so the inn heats it with a boiler and feeds it in from the tub floor, free-flowing without recirculation or chlorine, and covers the tubs with lids to keep the precious water warm.
The bar length shows how abundant each component is compared to thresholds that make it "distinctive" (therapeutic spring standards, beauty spring criteria, etc.).
A rare radioactive spring where trace radiation absorbed via inhalation and skin is expected to stimulate cells (the "hormesis effect").
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.
The tubs are covered with lids to keep the water warm, so it can be hot right after the lid comes off; stir and check the temperature first. Radioactive springs are traditionally enjoyed with slow, relaxed soaks, but get out early if it feels too hot, and replace the lid afterward.
With 113.6 Bq/kg of radon, this radioactive spring is traditionally associated with helping relieve pain and supporting the body's own defenses, while its light 0.207 g/kg mineral content feels soft on the skin and may support deep relaxation during long, easy soaks.
Beware of hot water right after the lid is removed and check the temperature before entering; avoid overheating from long soaks and drink water afterward.
※ See the analysis data below for detailed contraindications
ANALYSIS DATAView all analysis fields ▼
Source Info
- Source name
- Deyu Onsen Doshun-no-Iwaya (Well No. 2, Outer Casing)
- Spring type
- Simple Hot Spring
- Source temperature
- 30.6℃
- pH
- 6.8
- Flow rate
- 31 L/min
- Flow type
- 掘削自噴
- Osmotic pressure
- 低張性
Analysis Document
- Analysis date
- 2014-10-24
- Analyst organization
- 一般財団法人新潟県環境分析センター
- Registration No.
- 新潟県（登）理企第4号
Cations
- Lithium ion Li⁺
- 0.00 mg/kg
- Sodium ion Na⁺
- 30.5 mg/kg
- Potassium ion K⁺
- 1.1 mg/kg
- Ammonium ion NH₄⁺
- 0.70 mg/kg
- Magnesium ion Mg²⁺
- 0.20 mg/kg
- Calcium ion Ca²⁺
- 23.5 mg/kg
- Aluminum ion Al³⁺
- 0.00 mg/kg
- Manganese ion Mn²⁺
- 0.00 mg/kg
- Iron(II) ion Fe²⁺
- 0.00 mg/kg
- Zinc ion Zn²⁺
- 0.00 mg/kg
- Lead ion Pb²⁺
- < 0.005 mg/kg
- Strontium ion Sr²⁺
- 0.20 mg/kg
- Barium ion Ba²⁺
- 0.00 mg/kg
- Copper ion Cu²⁺
- 0.00 mg/kg
- Cadmium ion Cd²⁺
- < 0.001 mg/kg
- Total cations
- 0.06 mg/kg
Anions
- Fluoride ion F⁻
- 0.30 mg/kg
- Chloride ion Cl⁻
- 7.2 mg/kg
- Hydrogen sulfide ion HS⁻
- 0.00 mg/kg
- Thiosulfate ion S₂O₃²⁻
- 0.00 mg/kg
- Sulfate ion SO₄²⁻
- 72.8 mg/kg
- Bicarbonate ion HCO₃⁻
- 36.0 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⁻
- 0.00 mg/kg
- Nitrite ion NO₂⁻
- 0.00 mg/kg
- Nitrate ion NO₃⁻
- 0.00 mg/kg
- Hydrogen phosphate HPO₄²⁻
- 0.30 mg/kg
- Total anions
- 0.12 mg/kg
Undissociated Components
- Metasilicic acid H₂SiO₃
- 34.3 mg/kg
- Metaboric acid HBO₂
- 0.00 mg/kg
- Total undissociated
- 0.03 mg/kg
Dissolved Gas
- Free carbon dioxide CO₂
- 9.6 mg/kg
- Free hydrogen sulfide H₂S
- 0.00 mg/kg
- Total dissolved gas
- 0.01 mg/kg
Trace Components
- Radon Rn
- 113.6 Bq/kg
Totals
- Total dissolved substances
- 0.21 mg/kg
- Component total
- 0.22 mg/kg
- Evaporation residue
- 0.20 mg/kg
Usage
- Heating
- Yes（公式温泉ページ『◆加温あり』。温泉手帖（2018）『温水ボイラーを通して加温した温泉を湯底から出している源泉かけ流し』。）
- Dilution
- No
- Recycle / Filter
- No
- Additives
- No
- Disinfection
- No
Indications & Contraindications
- Bathing indications
- Hyperuricemia (gout), Rheumatoid arthritis, Ankylosing spondylitis
- General indications
- High blood pressure (mild), Autonomic instability, Insomnia, Depression, 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), Undergoing radiation therapy, pregnancy (radioactive springs)
Drinking
- Drinkability
- Not drinkable
