Tenjin Gensen
Analysis UnverifiedThis is a representative 'Kinsen' (golden spring) of Arima Onsen, one of Japan's three ancient hot springs. Rich in iron and salt, its waters turn a distinctive reddish-brown upon contact with air. These dense minerals provide deep, lasting warmth, while a salt veil on the skin helps retain moisture, leaving it feeling smooth. Perfect for those struggling with chronic fatigue or poor circulation, or anyone seeking to refresh mind and body. It supports those wishing to regain vitality through the power of its potent waters.
The bar length shows how abundant each component is compared to thresholds that make it "distinctive" (therapeutic spring standards, beauty spring criteria, etc.).
Undissociated boric acid with antibacterial action that keeps the skin surface clean.
Salinity comparable to seawater. The salt film traps heat for outstanding warmth ("hot bath spring").
Salt forms a thin film on the skin, retaining heat after bathing. Helps with poor circulation.
- Iron40.5 mg/kg
- Feel
- Turns reddish-brown in the air, with a rusty-iron smell.
- Said to
- Said to warm the body; where drinking is permitted, said to help iron-deficiency anemia.
- Note
- May stain white towels and swimwear.
- Chloride (salt)21130 mg/kg
- Feel
- Tastes salty; the warmth lasts after you get out.
- Said to
- Salt is said to form a film on the skin that keeps in heat and moisture. Bathing indications include cuts, poor circulation and dry skin.
- Note
- May sting cuts. Strong salty water can tire you—avoid long soaks.
- Metasilicic acid121 mg/kg
- Feel
- Your skin may feel smoother.
- Said to
- 50 mg/kg or more is said to mark a “skin-beautifying spring”; it is also used in skincare.
- Note
- The “skin-beautifying” label is a common rule of thumb, not a legal standard.
- Source temperature99.4℃
- Feel
- The source is 42°C or hotter; the bath may be on the hot side.
- Said to
- Heat is said to boost circulation and warm the body.
- Note
- Older people and those with high blood pressure or heart conditions should avoid baths of 42°C or more. Keep soaks short.
Effects are general descriptions based on the Ministry of the Environment’s indications by spring type, not a guarantee.
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.
Due to its highly concentrated strong salt nature, avoid long soaks and start with a 5-minute bath. After bathing, gently pat your skin dry with a towel without rinsing off the spring water to maintain the warming effect of the salt components.
Containing a remarkable 21130 mg/kg of chloride ions, this hypertonic spring offers exceptional 'restorative warmth' that heats the body to its core. It is especially recommended for those with poor circulation. It is also traditionally associated with helping to 'relieve pain' in muscles and joints.
This is a potent spring, so please avoid long soaks. Refrain from bathing after consuming alcohol or when you are not feeling well.
※ See the analysis data below for detailed contraindications
ANALYSIS DATAView all analysis fields ▼
Source Info
- Source name
- Tenjin Gensen
- Spring type
- Iron-containing Sodium Chloride strong saline Hot Spring
- Source temperature
- 99.4℃
- pH
- 6.6
- Flow rate
- 53 L/min
- Flow type
- Self-flowing
- Osmotic pressure
- Hypertonic
Analysis Document
- Analysis date
- 2019-10-25
- Analyst organization
- 公益財団法人 中央温泉研究所
- Registration No.
- 14 健地衛第1号
Cations
- Sodium ion Na⁺
- 10470 mg/kg
- Potassium ion K⁺
- 2005 mg/kg
- Ammonium ion NH₄⁺
- 8.6 mg/kg
- Magnesium ion Mg²⁺
- 76.4 mg/kg
- Calcium ion Ca²⁺
- 1725 mg/kg
- Aluminum ion Al³⁺
- 0.30 mg/kg
- Manganese ion Mn²⁺
- 13.7 mg/kg
- Iron(II) ion Fe²⁺
- 40.5 mg/kg
- Total cations
- 14270 mg/kg
Anions
- Fluoride ion F⁻
- 1.6 mg/kg
- Chloride ion Cl⁻
- 21130 mg/kg
- Sulfate ion SO₄²⁻
- 20.8 mg/kg
- Bicarbonate ion HCO₃⁻
- 244 mg/kg
- Bromide ion Br⁻
- 38.8 mg/kg
- Iodide ion I⁻
- 4.9 mg/kg
- Total anions
- 21440 mg/kg
Undissociated Components
- Metasilicic acid H₂SiO₃
- 121 mg/kg
- Metaboric acid HBO₂
- 257 mg/kg
- Total undissociated
- 379 mg/kg
Dissolved Gas
- Free carbon dioxide CO₂
- 189 mg/kg
- Total dissolved gas
- 189 mg/kg
Totals
- Total dissolved substances
- 36090 mg/kg
- Component total
- 36280 mg/kg
- Evaporation residue
- 36610 mg/kg
Usage
- Heating
- No
- Dilution
- No
- Recycle / Filter
- Filtered
- Additives
- No
- Disinfection
- No
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
