Natural Hot Springs and Pools | Chemical Analysis | The effect of Temperature on Mineral Water Therapy | Hours of Operation | Why are some Pools Cloudier than Others?

Natural Hot Mineral Springs, Pools & Waterfalls

Our freeform, landscaped pools provide our guests with great views of the volcano and a multitude of options.  Our Arenal hot springs with temperatures ranging from 83 ˚F to 103˚F and environments that vary from raging waterfalls to tranquil forest experiences our guests can find the perfect pool for their mood and the current weather conditions. 

Click for: Chemical Analysis of our Hot Springs and The Therapeutic Effects of its Minerals and Temperature

About the Resort


Las Lagunas (The Lagoons)   Located at the base of the reception building this area  encompasses two acres of lush landscaping and an assortment of multi-level sun and shade terraces surrounding twelve pools. Eight of the pools are fed directly by water pumped from our Hot Mineral Springs and the other four are chlorinated but heated to various temperatures by our Hot Springs through a heat exchange system.  These pools range in temperature from 84˚F to 104˚F.

Perdido Springs (Lost Springs) is a connected system of trails and seven spring fed pools located within a forest canyon just a short 100 meter walk from the lowest level of the Las Lagunas pools.  The trail to these Hot and Cold Springs, called the Heliconia Walk, is lined with different species of flowering Heliconias along with beautiful rainforest trees, plants and vines.   In the center of these pools is a small jungle bar called Los Perdidos (The Lost Ones) along with a water flume called the Monkey Slide.   These pools range in temperature from 91˚F to 104˚F.


Perdido Springs (Lost Springs)

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About Our Hot Mineral Springs

Our Hot Mineral Water is captured from natural springs near the river and are pumped up 420 feet (130 meters) to our pools.  Each night at closing the pools are drained, cleaned and refilled starting at 6:00 AM. During the hours of operation new hot water continually flows into the system.  The water is also circulated through a filtration system in these pools to eliminate some of the precipitated minerals and foreign contaminants.


Chemical Analysis of our Hot Springs and The Therapeutic Effects of its Minerals and Temperature

The therapeutic effects of various minerals have been extensively studied by European balneologists.  To be classified as a mineral spring the water needs to contain greater than 1,000 mg/l (PPM) of naturally dissolved solids.  Here at the Springs Resort and Spa our water contains over 1,500 mg/l (PPM) of dissolved solids and has a PH averaging 6.4 so its mineral/chemical composition lends it a slightly acidic nature common to many of the world's best hot springs.   Below is a summary of the effects of each of the minerals found in our hot springs and a comparison with other local hot springs.

Benefits of Bicarbonates (HCO3)-  – To qualify as a bicarbonate spring the water must contain at least 250 mg/l of bicarbonate gasses.  Ours contains the highest level in the Arenal area (751 mg/l) which is nearly three times the threshold required.  Balneologists generally agree that a high bicarbonate level is the most important component of medically therapeutic hot springs. Bicarbonates assist in opening peripheral blood vessels and improving circulation which aids against cardiovascular disease including hypertension and mild atherosclerosis.  For these conditions balneologists recommend a water temperature no higher than 100˚F.  Bicarbonate waters are also thought to have a positive effect on nervous system imbalances.

The Springs = 751 mg/l             Baldi = 263 mg/l

Benefits of Sodium (NA+)   Natural salts assist with the alleviation of arthritic symptoms, stimulate the body's lymphatic system and also help to maintain body fluid balance.

The Springs = 327 mg/l             Baldi = 244 mg/l

Benefits of Calcium (CA++)   Calcium strengthens bones to prevent osteoporosis and helps to regulate bodily functions.  It is essential to the function of many internal organs such as the heart. 

The Springs = 95 mg/l             Baldi = 106 mg/l

Benefits of Potassium (K+)  This element assists in the normalization of heart rhythms,  reduces high blood pressure, helps to eliminate body toxins and promotes healthy skin.

The Springs = 28 mg/l             Baldi = 39 mg/l

Benefits of Boron (B)   Boron builds muscle mass, increases brain activity and strengthens bones.  In addition it is an ophthalmologic irrigant that aids in cleansing your eyes.

The Springs = 7.8 mg/l             Baldi = 2.8 mg/l

Benefits of Magnesium (Mg++)  Magnesium maintains normal heart rhythms, assists in reducing high blood pressure and aids in eliminating body toxins.  It also converts blood sugar to energy and promotes healthy skin.

The Springs = 55 mg/l             Baldi = 57 mg/l

Benefits of Iron (Fe)  Iron builds up the quality of your blood, prevents stress and fatigue and improves skin tone.  It also builds resistance to disease and aids in muscle function.

The Springs = 3.0 mg/l             Baldi = ????

Benefits of Sulfur (S)  Hot Springs rich in Sulfur are used to address a wide variety of conditions, including skin infections, respiratory problems, and skin inflammations


The effect of Temperature on Mineral Water Therapy

More than the majority of European medical doctors who have conducted research into thermal water therapy agree that warm soaking in water 99˚F to 101˚F is more beneficial than higher temperatures.  In the U.S. the FDA and most state health departments do not permit pool or Jacuzzi heaters to exceed 104˚ F because of potential health hazards associated with prolonged exposure to higher temperatures. 
Scientific studies of thermal water therapy in Europe have found that warm water increases hydrostatic pressure in the body which leads to increased blood circulation and cell oxygenation as well as improving the performance of the body's waste elimination systems which aids in detoxification.   Metabolism is also stimulated which helps balance the digestive, endocrine and autonomic nervous systems.

Please do not use the hot springs if you have any of the following conditions.

Contraindications to Hot Water Natural Mineral Springs Therapy:

  • Conditions involving high fevers
  • Extreme Hypertension
  • Malignant tumors and cancerous conditions ( internal )
  • Liver, kidney, or circulation disorders
  • Conditions presenting the risk of hemorrhaging
  • Anemic Conditions
  • Pregnancy
  • Congestive heart failure, recent stroke, or recent heart attack
  • Bathing under the influence of drugs or alcohol

The existence of these or other metabolic conditions does not necessarily mean that there would be no benefit derived from utilizing mineral waters. It does mean, however, that there is a risk associated that may out way any benefit to utilizing hot waters. In such situations, individuals should consult with a medical doctor before bathing, or consult with a European medical balneologist.
In any case, soaking in mineral waters should not be done at excessively high temperatures without medical clearance when any contraindicated condition exists. A tepid to warm bath ( 95° F - 99° ) is as safe as taking a bath at home.

 Balneology is the scientific study of naturally occurring mineral waters and Balneotherapy is the practical study and application of the health benefits of these waters.   The primary scientific research by medical balneologists concerning the therapeutic uses of hot mineral water was conducted in Europe and Japan.  The FDA in the United States prohibits organizations from making unsubstantiated health claims concerning the medicinal value of natural mineral waters.

Hours of Operation

  • Cascadas Calientes        Open by 8:00 AM and Closed at 10:00 PM
  • Perdido Springs             Open by 10:00 AM and Closed at 10:00 PM
  • Club Rio Hot Spring        Open by 9:00 AM and Closed at 4:30 PM

This water contains naturally dissolved Salts (Na+),  Potassium (K+), Calcium (Ca++),  Iron (Fe), Sulfur (S), Magnesium (Mg++), Boron (B) and the most important aspect of mineral water, Bicarbonates (HCO3).  We are also very lucky to have a high value (427 mg/l) of organic Chlorine (Cl) that acts as a natural disinfectant.


 Why are some Pools Cloudier than Others?

Because Minerals are Precipitating out of the Water as it Cools and Oxidizes

Our hot springs come from underground water that is heated by volcanic vents and forced upwards toward the surface passing through mineral deposits and gases which dissolve in the water.  The minerals, salts and bicarbonates precipitate from a dissolved state as the water cools and it is exposed to oxygen in the air from our waterfalls.  The volcanic activity along with the ambient temperature and rain play a large factor in how fast the minerals precipitate and you may see changes in water clarity from one hour to the next.  If you want to soak in water with high levels of precipitated minerals you would choose the cloudier pools.   The clearer pools still have minerals but they remain in a dissolved state.

Consider our Sister Property Peace Lodge at La Paz Waterfall Gardens