Water profile — Myoken Ishiharaso

妙見1号Myoken Spring No. 1

曹BicarbonateSodium-Calcium-Magnesium Bicarbonate spring

Myoken Spring No. 1 is a bicarbonate water led by sodium, with calcium and magnesium close behind — the soft, jusou-sen side of Japanese hot-spring chemistry. It runs neutral and hypotonic: colorless and clear at the wellhead, though it leaves a faint metallic, astringent trace on the tongue and turns slightly brown and hazy by the time it reaches the lab bench. A generous 237.5 mg/kg of metasilicic acid puts it squarely in Japan's beauty-water family, and the posted certificate lists the water for cuts, peripheral circulation disorders, cold sensitivity and dry skin.

Good for

Smooth skin

Bicarbonate and alkalinity gently lift dead keratin while silica hydrates, leaving skin smooth. This is the basis of the beautifying-water (bijin-no-yu 美人の湯) reputation.

dry, rough skin

On the certificate:Dry skin

Aches & joints

Warmth eases stiffness and raises the pain threshold. Radon and sulfate springs show the strongest evidence for joint and muscle pain.

stiff shoulders

On the certificate:Muscle stiffness associated with motor paralysis

Recovery

Warmth and buoyancy lower stress markers and improve sleep; habitual bathing is linked to lower rates of depression.

fatigue, stress

On the certificate:Autonomic nervous system instabilityConvalescenceFatigue recoveryGeneral health improvement

Take care

Contraindications

Active stage of any illness (especially with fever)
Active tuberculosis
Advanced malignant tumor, severe anemia or other marked physical debilitation
Severe heart or lung disease causing breathlessness on slight exertion
Severe kidney disease accompanied by edema
Gastrointestinal bleeding
Any visible bleeding
Acute exacerbation of a chronic illness

Full composition

The bar is each ion's share of charge (mval%) within its group; over 20% names the spring. Gases, silica and trace metals are measured by mass only.

Cationsshare of charge (mval%)

Sodiumsalt's cation — pairs with chloride to make the water saltyNa⁺228mgP57 national37%
Calciumsettling and calming; can leave a white mineral bloomCa²⁺157mgP82 national29%
Magnesiummild; a laxative if you drink itMg²⁺92.8mgP92 national28%
Potassiumminor; matters for drinking limitsK⁺43.5mgP83 national4%
LithiumLi⁺1.0mgP74 national0.5%
AmmoniumNH₄⁺2.3mgP83 national0.5%
Iron (II)Fe²⁺2.0mgP74 national0.3%
StrontiumSr²⁺0.20mgP42 national0.0%

Anionsshare of charge (mval%)

Bicarbonate"soda" — softens skin, leaves it smoothHCO₃⁻1,251mgP93 national74%
Chloridetable-salt anion — coats the skin and holds heat inCl⁻172mgP54 national17%
Sulfate"gypsum / Glauber's salt" — vessels and wound healingSO₄²⁻121mgP58 national9%
Hydrogen phosphateHPO₄²⁻0.40mgP68 national0.0%
BromideBr⁻0.30mgP37 national0.0%

Non-dissociatedmeasured by mass

Metasilicic acidmetasilicic acid — a natural moisturizer for silky skinH₂SiO₃238mgP93 national
Metaboric acidmetaboric acid — mildly antibacterialHBO₂28.7mgP79 national
Metaarsenious acidHAsO₂0.20mgP68 national

Dissolved gasesmeasured by mass

Free carbon dioxidefizz — widens blood vessels (strong above 1000 mg/kg)CO₂431mgP95 national
Free hydrogen sulfide"egg" smell — opens vessels, antibacterialH₂S< —mg

Trace metalsmeasured by mass

CadmiumCd< —mg
CopperCu< —mg
Mercurytoxic trace — part of the drinking-safety checkHg< —mg
LeadPb< —mg

Measured at the source

6.90

Neutral

Source temperature

54.3°C

Hot

Tonicity

2.34g/kg

Hypotonic

Free CO₂

431mg/kg

Typical

Radon

3.80Bq/kg

Low

On the certificate

Chronic muscle or joint pain and stiffness (rheumatoid arthritis, osteoarthritis, lower back pain, neuralgia, frozen shoulder, bruises, sprains — chronic phase)
Cold sensitivity
Peripheral circulation disorders
Reduced gastrointestinal function (heaviness, bloating)
Mild hypertension
Impaired glucose tolerance (diabetes)
Mild hypercholesterolemia
Mild asthma or emphysema
Hemorrhoid pain
Stress-related symptoms (sleep disorders, depressed mood)
Cuts

Evidence

妙見31号Myoken Spring No. 31

曹BicarbonateSodium-Magnesium-Calcium Bicarbonate spring

Myoken Spring No. 31 feeds the drinking fountain rather than a bath — the posted certificate states plainly that bathing is not permitted for this source. It is a sodium-led bicarbonate water carrying magnesium and calcium, neutral and hypotonic, colorless and clear at the wellhead with only the faintest astringent trace on the tongue. Metasilicic acid runs to 219.6 mg/kg, and the certificate approves the water for drinking against gastric and duodenal ulcers, reflux esophagitis, impaired glucose tolerance (diabetes) and hyperuricemia (gout).