Water profile — Hotel Urashima

磯ノ湯5号泉Iso-no-yu Spring No. 5

塩ChlorideSodium-Calcium Chloride spring · +Sulfur

A sodium- and calcium-led, sulfur-bearing chloride spring. At the source the water is faintly pale yellow and clear, with a light salty tang and the characteristic rotten-egg note of hydrogen sulfide. Weakly alkaline and soft on the skin, it is moderately mineralized with noticeable body, and carries a real sulfur load (total sulfur 12.1 mg/kg).

Good for

Warming

Salt forms a film on the skin that slows heat loss, so the warmth lingers long after the bath (the classic heat-keeping water, nettō 熱の湯).

cold sensitivity

Skin conditions

Sulfur and acidic waters are antibacterial and keratolytic, studied for atopic dermatitis and psoriasis.

atopic skin, eczema

Circulation

Skin-absorbed CO₂ and hydrogen sulfide relax the vessel walls; carbon-dioxide springs can raise peripheral blood flow several-fold.

tired legs

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

Cuts

Mineral-rich chloride, sulfate and sulfur waters have a long-recorded soothing effect on minor cuts and slow-healing skin.

minor wounds

Recovery

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

fatigue, stress

Take care

Sensitive-skin caution

Strongly acidic or sulfur-rich water can sting broken, atopic-flare, or dry elderly skin. Ease in slowly and rinse off if it stings.

broken or dry skin

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⁺705mgP81 national72%
Calciumsettling and calming; can leave a white mineral bloomCa²⁺202mgP85 national24%
Magnesiummild; a laxative if you drink itMg²⁺15.6mgP67 national3%
PotassiumK⁺10.6mgP47 national0.6%
AmmoniumNH₄⁺1.8mgP79 national0.2%
LithiumLi⁺0.60mgP61 national0.2%
StrontiumSr²⁺2.1mgP85 national0.1%
ManganeseMn²⁺0.10mgP36 national0.0%
BariumBa²⁺0.20mgP74 national
Aluminumshows up in acidic volcanic waterAl³⁺< —mg
Iron (II)rusts brown in air; iron for anemia when drinkableFe²⁺< —mg
Iron (III)Fe³⁺< —mg
Hydrogenmakes the water acidic — sharp and bactericidalH⁺< —mg

Anionsshare of charge (mval%)

Chloridetable-salt anion — coats the skin and holds heat inCl⁻1,437mgP84 national92%
Sulfate"gypsum / Glauber's salt" — vessels and wound healingSO₄²⁻113mgP57 national6%
BicarbonateHCO₃⁻21.5mgP13 national0.8%
ThiosulfateS₂O₃²⁻14.0mgP96 national0.6%
FluorideF⁻4.0mgP70 national0.5%
Hydrogen sulfideHS⁻4.0mgP88 national0.3%
BromideBr⁻4.7mgP80 national0.1%
Carbonatestrongly alkaline; slippery feelCO₃²⁻< —mg
Hydrogen phosphateHPO₄²⁻< —mg
NitrateNO₃⁻< —mg

Non-dissociatedmeasured by mass

Metasilicic acidmetasilicic acid — a natural moisturizer for silky skinH₂SiO₃29.9mgP13 national
Metaboric acidmetaboric acid — mildly antibacterialHBO₂4.0mgP30 national
Metaarsenious acidHAsO₂< —mg

Dissolved gasesmeasured by mass

Free carbon dioxidefizz — widens blood vessels (strong above 1000 mg/kg)CO₂0.20mgP13 national
Free hydrogen sulfide"egg" smell — opens vessels, antibacterialH₂S0.20mgP68 national

Measured at the source

pH

8.30

Weakly alkaline

Source temperature

41.8°C

Warm

Tonicity

2.50g/kg

Hypotonic

Flow rate

61L/min

Typical

Free CO₂

0.20mg/kg

Low

Free H₂S

0.20mg/kg

Low

Evidence

磯の湯1号泉Iso-no-yu Spring No. 1

塩ChlorideSodium-Calcium Chloride spring · +Sulfur

A sodium- and calcium-led, sulfur-bearing chloride spring. At the source it is pale yellow and clear, with a mild salty edge and the rotten-egg note of hydrogen sulfide. Weakly alkaline and soft on the skin, it is moderately mineralized with noticeable body and carries a real sulfur load (total sulfur 9.6 mg/kg).

Good for

Warming

Salt forms a film on the skin that slows heat loss, so the warmth lingers long after the bath (the classic heat-keeping water, nettō 熱の湯).

cold sensitivity

Skin conditions

Sulfur and acidic waters are antibacterial and keratolytic, studied for atopic dermatitis and psoriasis.

atopic skin, eczema

Circulation

Skin-absorbed CO₂ and hydrogen sulfide relax the vessel walls; carbon-dioxide springs can raise peripheral blood flow several-fold.

tired legs

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

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

Cuts

Mineral-rich chloride, sulfate and sulfur waters have a long-recorded soothing effect on minor cuts and slow-healing skin.

minor wounds

Recovery

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

fatigue, stress

Take care

Sensitive-skin caution

Strongly acidic or sulfur-rich water can sting broken, atopic-flare, or dry elderly skin. Ease in slowly and rinse off if it stings.

broken or dry skin

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⁺962mgP84 national69%
Calciumsettling and calming; can leave a white mineral bloomCa²⁺300mgP88 national25%
Magnesiummild; a laxative if you drink itMg²⁺39.2mgP82 national5%
PotassiumK⁺17.5mgP59 national0.7%
LithiumLi⁺0.70mgP64 national0.2%
StrontiumSr²⁺2.8mgP86 national0.1%
AmmoniumNH₄⁺0.60mgP53 national0.1%
ManganeseMn²⁺0.30mgP53 national0.0%
BariumBa²⁺0.20mgP74 national
Aluminumshows up in acidic volcanic waterAl³⁺< —mg
Iron (II)rusts brown in air; iron for anemia when drinkableFe²⁺< —mg
Iron (III)Fe³⁺< —mg
Hydrogenmakes the water acidic — sharp and bactericidalH⁺< —mg

Anionsshare of charge (mval%)

Chloridetable-salt anion — coats the skin and holds heat inCl⁻1,924mgP86 national91%
Thiosulfateoxidized sulfurS₂O₃²⁻192mgP100 national7%
Bicarbonate"soda" — softens skin, leaves it smoothHCO₃⁻37.5mgP22 national1%
SulfateSO₄²⁻8.6mgP20 national0.4%
FluorideF⁻3.9mgP69 national0.3%
BromideBr⁻6.9mgP85 national0.1%
Carbonatestrongly alkaline; slippery feelCO₃²⁻< —mg
Hydrogen phosphateHPO₄²⁻< —mg
Hydrogen sulfidesulfur character — antibacterialHS⁻< —mg

Non-dissociatedmeasured by mass

Metasilicic acidmetasilicic acid — a natural moisturizer for silky skinH₂SiO₃32.0mgP15 national
Metaboric acidmetaboric acid — mildly antibacterialHBO₂3.3mgP26 national
Metaarsenious acidHAsO₂< —mg

Dissolved gasesmeasured by mass

Free carbon dioxidefizz — widens blood vessels (strong above 1000 mg/kg)CO₂1.9mgP21 national
Free hydrogen sulfide"egg" smell — opens vessels, antibacterialH₂S0.80mgP75 national

Measured at the source

pH

8.10

Weakly alkaline

Source temperature

43.4°C

Hot

Tonicity

3.53g/kg

Hypotonic

Flow rate

203L/min

Typical

Free CO₂

1.90mg/kg

Low

Free H₂S

0.80mg/kg

Low

Evidence

磯ノ湯3号泉Iso-no-yu Spring No. 3

塩ChlorideSodium Chloride spring · +Sulfur

A sodium-led, sulfur-bearing chloride spring. At the source the water is a clear, bright yellow with a distinct salty taste and the rotten-egg note of hydrogen sulfide. Weakly alkaline and soft on the skin, it is richly mineralized and leaves a mineral film on the skin, with an abundant sulfur load (total sulfur 22.7 mg/kg).

Good for

Warming

Salt forms a film on the skin that slows heat loss, so the warmth lingers long after the bath (the classic heat-keeping water, nettō 熱の湯).

cold sensitivity

Skin conditions

Sulfur and acidic waters are antibacterial and keratolytic, studied for atopic dermatitis and psoriasis.

atopic skin, eczema

Circulation

Skin-absorbed CO₂ and hydrogen sulfide relax the vessel walls; carbon-dioxide springs can raise peripheral blood flow several-fold.

tired legs

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

Cuts

Mineral-rich chloride, sulfate and sulfur waters have a long-recorded soothing effect on minor cuts and slow-healing skin.

minor wounds

Recovery

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

fatigue, stress

Take care

Sensitive-skin caution

Strongly acidic or sulfur-rich water can sting broken, atopic-flare, or dry elderly skin. Ease in slowly and rinse off if it stings.

broken or dry skin

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⁺1,914mgP91 national74%
Calciumsettling and calming; can leave a white mineral bloomCa²⁺308mgP89 national14%
Magnesiummild; a laxative if you drink itMg²⁺149mgP94 national11%
Potassiumminor; matters for drinking limitsK⁺45.7mgP82 national1%
StrontiumSr²⁺3.3mgP87 national0.1%
LithiumLi⁺0.60mgP61 national0.1%
AmmoniumNH₄⁺0.70mgP56 national0.0%
Manganesetrace; companion to iron springsMn²⁺0.70mgP72 national
BariumBa²⁺0.20mgP74 national
Aluminumshows up in acidic volcanic waterAl³⁺< —mg
Iron (II)rusts brown in air; iron for anemia when drinkableFe²⁺< —mg
Iron (III)Fe³⁺< —mg
Hydrogenmakes the water acidic — sharp and bactericidalH⁺< —mg

Anionsshare of charge (mval%)

Chloridetable-salt anion — coats the skin and holds heat inCl⁻3,550mgP91 national91%
Sulfate"gypsum / Glauber's salt" — vessels and wound healingSO₄²⁻389mgP81 national7%
BicarbonateHCO₃⁻62.0mgP33 national0.9%
ThiosulfateS₂O₃²⁻23.2mgP97 national0.4%
Hydrogen sulfideHS⁻9.2mgP95 national0.3%
FluorideF⁻3.7mgP69 national0.2%
BromideBr⁻12.5mgP89 national0.1%
IodideI⁻0.50mgP69 national0.0%
Carbonatestrongly alkaline; slippery feelCO₃²⁻< —mg
Hydrogen phosphateHPO₄²⁻< —mg
NitrateNO₃⁻< —mg

Non-dissociatedmeasured by mass

Metasilicic acidmetasilicic acid — a natural moisturizer for silky skinH₂SiO₃30.5mgP13 national
Metaboric acidmetaboric acid — mildly antibacterialHBO₂5.3mgP39 national
Metaarsenious acidHAsO₂< —mg

Dissolved gasesmeasured by mass

Free hydrogen sulfide"egg" smell — opens vessels, antibacterialH₂S0.50mgP73 national
Free carbon dioxidefizz — widens blood vessels (strong above 1000 mg/kg)CO₂< —mg

Measured at the source

pH

8.30

Weakly alkaline

Source temperature

41.4°C

Warm

Tonicity

6.51g/kg

Hypotonic

Flow rate

150L/min

Typical

Free H₂S

0.50mg/kg

Low

Evidence

磯ノ湯2号泉Iso-no-yu Spring No. 2

塩ChlorideSodium Chloride spring · +Sulfur

A sodium-led, sulfur-bearing chloride spring. At the source the water is pale yellow and clear, faintly salty and carrying the rotten-egg note of hydrogen sulfide. Weakly alkaline and soft on the skin, it is richly mineralized and leaves a mineral film on the skin, with an abundant sulfur load (total sulfur 37.1 mg/kg).

Good for

Warming

Salt forms a film on the skin that slows heat loss, so the warmth lingers long after the bath (the classic heat-keeping water, nettō 熱の湯).

cold sensitivity

Skin conditions

Sulfur and acidic waters are antibacterial and keratolytic, studied for atopic dermatitis and psoriasis.

atopic skin, eczema

Circulation

Skin-absorbed CO₂ and hydrogen sulfide relax the vessel walls; carbon-dioxide springs can raise peripheral blood flow several-fold.

tired legs

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

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

Cuts

Mineral-rich chloride, sulfate and sulfur waters have a long-recorded soothing effect on minor cuts and slow-healing skin.

minor wounds

Recovery

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

fatigue, stress

Take care

Sensitive-skin caution

Strongly acidic or sulfur-rich water can sting broken, atopic-flare, or dry elderly skin. Ease in slowly and rinse off if it stings.

broken or dry skin

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⁺1,332mgP88 national73%
Calciumsettling and calming; can leave a white mineral bloomCa²⁺276mgP87 national17%
Magnesiummild; a laxative if you drink itMg²⁺83.9mgP90 national9%
PotassiumK⁺30.5mgP75 national1.0%
LithiumLi⁺0.60mgP61 national0.1%
StrontiumSr²⁺2.8mgP86 national0.1%
AmmoniumNH₄⁺0.60mgP53 national0.0%
ManganeseMn²⁺0.40mgP59 national0.0%
BariumBa²⁺0.20mgP74 national
Aluminumshows up in acidic volcanic waterAl³⁺< —mg
Iron (II)rusts brown in air; iron for anemia when drinkableFe²⁺< —mg
Iron (III)Fe³⁺< —mg
Hydrogenmakes the water acidic — sharp and bactericidalH⁺< —mg

Anionsshare of charge (mval%)

Chloridetable-salt anion — coats the skin and holds heat inCl⁻2,747mgP89 national92%
Sulfate"gypsum / Glauber's salt" — vessels and wound healingSO₄²⁻228mgP68 national6%
Bicarbonate"soda" — softens skin, leaves it smoothHCO₃⁻61.6mgP33 national1%
ThiosulfateS₂O₃²⁻32.3mgP98 national0.7%
Hydrogen sulfideHS⁻17.3mgP98 national0.6%
FluorideF⁻4.1mgP72 national0.3%
BromideBr⁻9.0mgP88 national0.1%
Carbonatestrongly alkaline; slippery feelCO₃²⁻< —mg
Hydrogen phosphateHPO₄²⁻< —mg
NitrateNO₃⁻< —mg

Non-dissociatedmeasured by mass

Metasilicic acidmetasilicic acid — a natural moisturizer for silky skinH₂SiO₃33.5mgP15 national
Metaboric acidmetaboric acid — mildly antibacterialHBO₂5.0mgP37 national
Metaarsenious acidHAsO₂< —mg

Dissolved gasesmeasured by mass

Free carbon dioxidefizz — widens blood vessels (strong above 1000 mg/kg)CO₂2.0mgP21 national
Free hydrogen sulfide"egg" smell — opens vessels, antibacterialH₂S2.0mgP81 national

Measured at the source

pH

8.00

Weakly alkaline

Source temperature

46.1°C

Hot

Tonicity

4.87g/kg

Hypotonic

Flow rate

207L/min

Typical

Free CO₂

2.00mg/kg

Low

Free H₂S

2.00mg/kg

High

Evidence

岩窟湯・翁湯・赤島1号泉・赤島2号泉・浦島湯・鯨湯Blended source (Gankutsu-yu, Okina-yu, Akashima No. 1, Akashima No. 2, Urashima-yu, Kujira-yu)

塩ChlorideSodium-Calcium Chloride spring · +Sulfur

A blend of six wells served from a relay tank, this is a sodium- and calcium-led, sulfur-bearing chloride spring. Sampled from the mixing tank as a blended source at a hot 51 °C, the water at the source is pale yellow and clear with a faint rotten-egg note of hydrogen sulfide. Neutral in pH and gentle on the skin, it is richly mineralized and leaves a mineral film, with an abundant sulfur load (total sulfur 28.6 mg/kg).

Good for

Warming

Salt forms a film on the skin that slows heat loss, so the warmth lingers long after the bath (the classic heat-keeping water, nettō 熱の湯).

cold sensitivity

Skin conditions

Sulfur and acidic waters are antibacterial and keratolytic, studied for atopic dermatitis and psoriasis.

atopic skin, eczema

Circulation

Skin-absorbed CO₂ and hydrogen sulfide relax the vessel walls; carbon-dioxide springs can raise peripheral blood flow several-fold.

tired legs

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

Cuts

Mineral-rich chloride, sulfate and sulfur waters have a long-recorded soothing effect on minor cuts and slow-healing skin.

minor wounds

Recovery

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

fatigue, stress

Take care

Sensitive-skin caution

Strongly acidic or sulfur-rich water can sting broken, atopic-flare, or dry elderly skin. Ease in slowly and rinse off if it stings.

broken or dry skin

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⁺1,614mgP90 national71%
Calciumsettling and calming; can leave a white mineral bloomCa²⁺406mgP91 national20%
Magnesiummild; a laxative if you drink itMg²⁺91.8mgP91 national8%
PotassiumK⁺35.5mgP79 national0.9%
StrontiumSr²⁺4.5mgP88 national0.1%
LithiumLi⁺0.40mgP50 national0.1%
AmmoniumNH₄⁺0.70mgP56 national0.0%
ManganeseMn²⁺0.30mgP53 national0.0%
BariumBa²⁺0.20mgP74 national0.0%
Aluminumshows up in acidic volcanic waterAl³⁺< —mg
Iron (II)rusts brown in air; iron for anemia when drinkableFe²⁺< —mg
Iron (III)Fe³⁺< —mg
Hydrogenmakes the water acidic — sharp and bactericidalH⁺< —mg

Anionsshare of charge (mval%)

Chloridetable-salt anion — coats the skin and holds heat inCl⁻3,171mgP90 national93%
Sulfate"gypsum / Glauber's salt" — vessels and wound healingSO₄²⁻263mgP71 national6%
ThiosulfateS₂O₃²⁻37.7mgP99 national0.7%
BicarbonateHCO₃⁻35.2mgP20 national0.6%
FluorideF⁻4.2mgP72 national0.2%
BromideBr⁻10.8mgP89 national0.1%
Iodideyellows in air; helps blood lipidsI⁻0.60mgP73 national
Carbonatestrongly alkaline; slippery feelCO₃²⁻< —mg
Hydrogen phosphateHPO₄²⁻< —mg
NitrateNO₃⁻< —mg

Non-dissociatedmeasured by mass

Metasilicic acidmetasilicic acid — a natural moisturizer for silky skinH₂SiO₃44.3mgP25 national
Metaboric acidmetaboric acid — mildly antibacterialHBO₂5.6mgP39 national
Metaarsenious acidHAsO₂< —mg

Dissolved gasesmeasured by mass

Free carbon dioxidefizz — widens blood vessels (strong above 1000 mg/kg)CO₂8.2mgP36 national
Free hydrogen sulfide"egg" smell — opens vessels, antibacterialH₂S2.3mgP81 national

Measured at the source

pH

7.40

Neutral

Source temperature

51.2°C

Hot

Tonicity

5.73g/kg

Hypotonic

Flow rate

613L/min

High

Free CO₂

8.20mg/kg

Low

Free H₂S

2.30mg/kg

High