Glenwood Hot Springs Lodge, Pool and Spa in Glenwood Springs CO

How We Keep Our Pool Clean and Safe

Every year, Glenwood Hot Springs Resort hosts thousands of visitors who come to soak, play and relax in its geothermal waters. Here’s how we keep over a million gallons of water in our pools perfectly pristine.

Known famously as the world’s largest hot springs pool, Glenwood Hot Springs annually welcomes countless visitors to experience a genuine natural wonder—soaking in a natural, historic, geothermally-heated hot spring. Visitors rightfully assume that when they take a dip in our water, it’s always clean. Maintaining our high water quality standards is a demanding task that takes time, training, teamwork and technology. Our entire team of pool maintenance technicians are Certified Pool Operators, and someone is on duty 24 hours a day, 7 days a week.

Regularly scheduled maintenance and a state-of-the-art ozone based filtration system keep the Glenwood Hot Springs Pool in immaculate condition. Even though the Glenwood Hot Springs Pool is open nearly every day of the year, there are approximately seven days when it’s closed for “routine maintenance.” Those days are anything but routine for pool staff.


Our pool and maintenance crews are highly trained and efficient. They begin by draining water from Glenwood Hot Springs’ two pools the night before the scheduled closing day. Because the combined pools contain over a million gallons of water, it takes eight to nine hours to completely drain! To empty the pools, workers dive down 12 feet to the bottom of the deep end and must first relieve ground water pressure via a series of valves before draining. If they didn’t do this, the pressure exerted by the ground water would be so great that it would lift up and destroy the concrete casing of the pool as it empties! 


Once the pool is drained, crews arrive early in the morning to get started. Regular maintenance tasks include power washing, inspecting, painting, servicing, repairing or replacing various components and systems including heat exchangers, valves, pumps and motors, filters, underwater lights and the ozone contact tank.

Because the hot spring water is rich in minerals, it leaves behind mineral deposits that build up over time. You’ll notice it on the gutter blocks along the edges of the pools where it adds to the natural beauty of the pool. The minerals also have a corrosive effect on various mechanisms, and along with regular maintenance, excess or damaging mineral deposits are cleaned up on maintenance days.

Since it takes a full 10 hours to refill the pools, crews work non-stop throughout the day to complete all the necessary jobs to get the pools ready to fill on time.  Come opening time the next day, Glenwood Hot Springs is ready to welcome guests as usual.


In addition to the dedicated cleaning days, the water in the Glenwood Hot Springs Pools is filtered and purified 24 hours a day at a rate equal to a complete changeover of water every six hours. The Glenwood Hot Springs also utilizes a state-of-the-art, custom-built ozone gas generator which resides in the filtration building up on the hill just north of the deep end of the pool. Chlorine, the typical disinfectant used in public pools, can irritate skin and eyes. The pool’s ozone treatment system reduces the amount of chlorine needed and thoroughly disinfects the pool water.

We are vigilant about our water quality, so that when you visit Glenwood Hot Springs Resort, you can soak in our geothermal hot springs and relax without a care in the world. Learn more about Glenwood Hot Springs at

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