Gero Onsen (Koda Pump Station)

Analysis Unverified
下呂温泉(幸田ポンプ所)
Silky Waters of the Heron

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 sent by the healing Buddha Yakushi. The Gero Onsen Koda pump station source gathers several centrally managed wells and sends them to inns across the Koda district. Its pH 9.4 alkaline water glides softly over the skin and lingers as a light, refreshed feeling afterward, soothing travelers who seek gentle rest.

AI Generated
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
9.4
Alkaline
Acidic ← 07 Neutral14 → Alkaline
Alkaline spring with notable slippery feel and keratin-softening effects. Rinse thoroughly with fresh water after bathing.
Caution: Rinse the body with fresh water after bathing.
TEMPERATURE
56.0
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
17.0 mg/kg

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

Metasilicic acidSee detail
66.7 mg/kg

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

Metaborate ionSee detail
5.4 mg/kg

Gentle antibacterial action that conditions the skin.

Carbonate ionSee detail
25.4 mg/kg

Slightly alkaline, softening dead skin cells.

Bicarbonate ionSee detail
38.7 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 unknownInformation 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 slippery pH 9.4 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 9.4 and 66.7 mg/kg of metasilicic acid, this water is traditionally associated with silky skin, softening the outer layer gently. 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°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 (Koda Pump Station)
Spring type
Alkaline Simple Hot Spring
Source temperature
56℃
pH
9.4

Analysis Document

Analysis date
2018-12-03
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⁺
104 mg/kg
Potassium ion K⁺
1.4 mg/kg
Magnesium ion Mg²⁺
< 0.1 mg/kg
Calcium ion Ca²⁺
2.5 mg/kg
Aluminum ion Al³⁺
0.09 mg/kg
Manganese ion Mn²⁺
< 0.001 mg/kg
Total cations
0.11 mg/kg

Anions

Fluoride ion F⁻
17.0 mg/kg
Chloride ion Cl⁻
81.2 mg/kg
Hydrogen sulfide ion HS⁻
0.30 mg/kg
Sulfate ion SO₄²⁻
11.0 mg/kg
Bicarbonate ion HCO₃⁻
38.7 mg/kg
Carbonate ion CO₃²⁻
25.4 mg/kg
Nitrate ion NO₃⁻
< 0.05 mg/kg
Arsenite ion AsO₂⁻
0.20 mg/kg
Metaborate ion BO₂⁻
5.4 mg/kg
Total anions
0.18 mg/kg

Undissociated Components

Metasilicic acid H₂SiO₃
66.7 mg/kg
Total undissociated
0.07 mg/kg

Dissolved Gas

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

Totals

Total dissolved substances
0.35 mg/kg
Component total
0.35 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)
Official site
Tattoo
Confirming
Private bath (Kashikiri)
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: 12:0018:00
Weekends & holidays: 12:0018:00
Day-use hot spring hours. Overnight guests can use the baths 24 hours (some baths may be unavailable during cleaning). Day-use requires prior inquiry.
Transit
2-minute drive from JR Takayama Line Gero Station (下呂駅) (shuttle bus available) or 7-minute walk. Shuttle bus available upon phone call after arriving at Gero Station.
Parking
Available (free). Capacity for 30 cars. No reservation required, but it is recommended to inform us when booking if you are coming by car.
Day use fee
¥1,000Day-use hot spring fee starts from 1000 yen. Operating hours and fees may change, so it is recommended to confirm with the facility in advance.
Facilities
Public BathPrivate BathGift ShopVending MachinesBanquet HallFoot BathLibraryWi-Fi
House rules
Bringing outside food and drinks into dining areas is prohibited (a corkage fee may apply). Additionally, a hot spring tax of 150 yen per person per night will be charged. An accommodation tax is scheduled to be introduced from October 1, 2025 (100 yen for stays under 5,000 yen, 200 yen for stays 5,000 yen or more. Children under 12 are exempt). Please contact us if checking in after 18:00, or if your dinner-inclusive plan will result in arrival after 18:00.
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

Tsurutsuru no Yu Gero Onsen Minoriso

From¥7,150/ person / night (tax incl.)
4.0(930)

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