Gero Onsen (Soto Pump Station)

Analysis Unverified
下呂温泉(送湯ポンプ所)
Smooth Waters of Gero Town

Gero Onsen counts among Japan's three famous springs, and legend holds that when its waters once vanished, a white heron alighted on the Masuda riverbank to reveal a new gush. The Gero Onsen Soto pump station source draws on several centrally managed wells and sends them on to inns throughout the hot-spring town. Its pH 8.9 alkaline water glides softly over the skin and lingers as a light, refreshed feeling, soothing travelers who stroll the hot-spring town and seek gentle rest.

AI Generated
単
SPRING TYPE
Simple Spring

Spring water that is gentle on the skin with a very low likelihood of irritation. Safe for bathing infants and those with sensitive skin.

See features & indications▾
Bathing indications
Autonomic instabilityInsomniaDepression
Definition :Total dissolved solids (excluding gases) below 1,000 mg/kg; water temperature 25°C or above.
Source: 環境省「あんしん・あんぜんな温泉利用のいろは」(監修:日本温泉気候物理医学会) ↗Read full article
PH VALUE
8.9
Alkaline
Acidic ← 07 Neutral14 → Alkaline
Alkaline (pH > 8.5). Strong soap-like cleansing and keratin-softening effects. The characteristic slippery feel begins to appear.
TEMPERATURE
56.2℃
Very Hot Spring
Very hot. Cannot be bathed in without significant dilution.
KEY MINERALS

The bar length shows how abundant each component is compared to thresholds that make it "distinctive" (therapeutic spring standards, beauty spring criteria, etc.).

Fluoride ionSee detail
10.3 mg/kg

Mild antibacterial action keeps the skin clean. Trace transdermal absorption supports tooth and bone health.

Metaboric acidSee detail
7.0 mg/kg

A trace component with gentle antibacterial and anti-inflammatory action.

Metasilicic acidSee detail
57.3 mg/kg

A natural moisturizer that leaves a hydrated feel on the skin.

Carbonate ionSee detail
24.1 mg/kg

Slightly alkaline, softening dead skin cells.

Bicarbonate ionSee detail
37.5 mg/kg

Softens dead skin cells for a silky bathing feel.

CHARACTER · COMPOSITION PROFILE
1234StimulationBactericidalSkin BeautyHeat RetentionRelaxation

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.

USAGE
Usage status is unknown — Information from facility postings or official sites has not been confirmed. Please check with staff on site.
▸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.

EFFECTS
Spring-specific indications (bathing)
Autonomic instabilityInsomniaDepression
General indications (bathing)
High blood pressure (mild)Rheumatoid arthritisChronic pain or stiffness in muscles and jointsMuscle stiffness due to motor paralysisGastrointestinal dysfunction
Contraindications
Acute illness (especially with fever)Active tuberculosisMalignant tumorsSevere heart diseaseRespiratory failureRenal failureBleeding disordersSevere anemiaAny actively progressing illnessPregnancy (especially early and late stages)
BATHING TIPS
AI Generated

With a smooth pH 8.9 alkaline touch, go light on soap and let the water glide over the skin. As a mild simple spring, it suits an unhurried 10 to 15 minute soak at a moderate temperature.

EFFECT STORY
AI Generated

With a pH of 8.9 and 57.3 mg/kg of metasilicic acid, this water is traditionally associated with silky skin, gently softening the outer layer. As a mild simple spring, it may also support deep relaxation on days when work or travel fatigue needs to be eased.

CAUTIONS
AI Generated

Avoid bathing during acute illness or with serious heart or lung conditions. The source reaches 56.2°C, so check the bath temperature before entering.

※ See the analysis data below for detailed contraindications

ANALYSIS DATAView all analysis fields ▼

Source Info

Source name
Gero Onsen (Soto Pump Station)
Spring type
Alkaline Simple Hot Spring
Source temperature
56.2℃
pH
8.9

Analysis Document

Analysis date
2013-11-25
Analyst organization
一般財団法人 岐阜県公衆衛生検査センター
Registration No.
岐阜県第二号

Cations

Sodium ion Na⁺
118 mg/kg
Potassium ion K⁺
2.2 mg/kg
Magnesium ion Mg²⁺
< 0.1 mg/kg
Calcium ion Ca²⁺
4.4 mg/kg
Aluminum ion Al³⁺
0.06 mg/kg
Manganese ion Mn²⁺
< 0.001 mg/kg
Iron(II) ion Fe²⁺
< 0.02 mg/kg
Total cations
0.12 mg/kg

Anions

Fluoride ion F⁻
10.3 mg/kg
Chloride ion Cl⁻
113 mg/kg
Hydrogen sulfide ion HS⁻
< 0.1 mg/kg
Sulfate ion SO₄²⁻
12.4 mg/kg
Bicarbonate ion HCO₃⁻
37.5 mg/kg
Carbonate ion CO₃²⁻
24.1 mg/kg
Nitrate ion NO₃⁻
0.40 mg/kg
Total anions
0.20 mg/kg

Undissociated Components

Arsenious acid HAsO₂
0.10 mg/kg
Metasilicic acid H₂SiO₃
57.3 mg/kg
Metaboric acid HBO₂
7.0 mg/kg
Total undissociated
0.06 mg/kg

Dissolved Gas

Free carbon dioxide CO₂
< 4 mg/kg
Free hydrogen sulfide H₂S
< 0.1 mg/kg

Totals

Total dissolved substances
0.39 mg/kg
Component total
0.39 mg/kg

Usage

Usage status
Unknown

Indications & Contraindications

Bathing indications
Autonomic instability, Insomnia, Depression
General indications
High blood pressure (mild), Rheumatoid arthritis, 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
FACILITY INFO
AI draft (unverified)
Private bath (Kashikiri)
Available
Room with private open-air bath
Available
About tattoos and onsen
Travelers with tattoos can still bathe comfortably in a private bath (Kashikiri) or a room with a private open-air bath.
Hours
Weekdays: 18:00〜20:00
Weekends & holidays: 18:00〜20:00
日帰り入浴の利用時間です。
Transit
JR下呂駅より徒歩5分。JR下呂駅から宿までタクシーにて無料で送迎あり(要事前連絡)。
Parking
無料駐車場完備。
Day use fee
¥1,000大人通常料金。
Facilities
大浴場露天風呂貸切露天風呂足湯売店湯上がりサロン喫茶貸切岩盤浴
This information may change without notice. Please contact the facility directly for accurate details.
How Long to Stay (Toji)
Start with 2 nights / 3 days

Japan’s Ministry of the Environment notes that even a short stay refreshes you. For a full therapeutic cure, around 2–3 weeks is the guideline.

More on toji length
Stay at this hotel
PR

Gero Onsen Gero Royal Hotel Miyatei

From¥15,500/ person / night (tax incl.)
4.2(2653)

Approx. lowest rate (varies by date & guests)

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✨ The descriptions, catch phrases, and translations on this page are generated by AI (Claude). pH, temperature, and component values are OCR-extracted from the official analysis report. Learn more