Caldera 73531 | 75 sq ft Utopia Spa Filter
TheĀ Caldera 73531 filter cartridgeĀ is aĀ factory-original replacementĀ covering a wide range of Caldera spas. WithĀ 75 square feetĀ of filtration acrossĀ 260 pleatsĀ of heavy-duty polyester, it delivers more efficient filtration and better water clarity ā so you spend less time cleaning and more time enjoying your hot tub.
Filtration is the quiet backbone of good spa water. Every soak leaves behindĀ body oils, lotions, hair, and fine debris, and the cartridge is what removes all of it before it clouds the water, feeds bacteria, or coats your plumbing. When a filter is worn or clogged, the effects spread everywhere: dull water, higher chemical use, softer jets, and aĀ pump and heater strainingĀ against restricted flow.
This cartridge is the workhorse of the Caldera lineup ā it serves more models across more series than any other size, fromĀ ParadiseĀ® SeriesĀ spas like Salina and Makena to Highland, Aquatic Melodies, and C-Series models. Caldera specifies aĀ heavy-duty polyesterĀ media designed to outlast cheaper alternatives, and aĀ semi-circular handleĀ on top makes lifting the cartridge out for cleaning effortless. Like all Caldera filters, it'sĀ made in the USA.
CalderaĀ®
CalderaĀ® Brand FAQs
Who makes Caldera Spas?
Caldera Spas was founded in1976and is manufactured by Watkins Wellness, a global industry leader that has built more than one million hot tubs. Caldera is recognized throughout the industry for performance, quality, and customer satisfaction ā including thirteen consecutive certifications for excellence in customer satisfaction from the consumer group SpaSearch.
What are the Caldera Spas series?
Caldera offers three primary series. The UtopiaĀ®Series is the flagship line ā a hydrotherapy powerhouse with architecturally inspired cabinetry, touchscreen controls, and premium features. The ParadiseĀ®Series blends practical and premium for mid-range luxury. The VacanzaĀ®Series delivers signature Caldera comfort and quality at an exceptional value. Caldera also offers a cold plunge.
Which filter does my Caldera spa use?
It depends on your series, model, and year. Caldera uses several different cartridges across its lineup, and even within the same model line the filter can change by year. The most reliable method is to pull your current filter and read the part number printed on it, or check your owner's manual. Also confirm how many cartridgesyour spa takes, since some models use more than one.
How often should I clean and replace my Caldera filter?
As a general rule,rinse with a garden hose every two to four weeks, working between the pleats, and deep clean periodically with a dedicated filter cleaner to dissolve the body oils a rinse can't remove. Replace the cartridge when the pleats are torn, flattened, or permanently discolored, or when cleaning no longer restores flow and water clarity.
Are genuine Caldera filters worth it compared to aftermarket?
Factory-original filters are built to the exact dimensions, filtration area, and flow characteristics your spa's circulation and jet systems were engineered around. An aftermarket filter that fits the opening may still restrict flow or filter less effectively, making your pump work harder and leaving your water less clear. Caldera filters use heavy-duty polyester designed to last far longer than cheaper alternatives, and they're made in the USA.
What water care system do Caldera spas use?
It varies by series. UtopiaĀ® and ParadiseĀ® Series spas are designed for the FreshWaterĀ® Salt System, which produces longer-lasting, natural-feeling water with less maintenance ā and FreshWaterĀ® IQ adds in-line self-monitoring that tells you what the water needs. VacanzaĀ® Series spas typically use FROGĀ® water care systems. Whichever system you run, clean filters and a consistent routine are what keep the water clear.
About CalderaĀ®
Founded inĀ 1976,Ā CalderaĀ® SpasĀ is one of the most heralded and trusted spa brands in the world. Caldera is manufactured byĀ Watkins WellnessĀ ā the global industry leader that has built more thanĀ one million hot tubsĀ ā and is recognized throughout the industry for performance, quality, and customer satisfaction.
What sets a Caldera apart is a relentless focus on how it actuallyĀ feels to use. Comfort is the essential element: deep, cradling seats and a texturedĀ Foot RidgeĀ®Ā keep you relaxed and seated even under powerful jets, perfectly positioned hydrotherapy melts tension away, and a whisper-quietĀ sound-dampening designĀ lets you actually unwind. Every detail is crafted to awaken the senses, from rich colors and contemporary cabinet styles to the organic contours of the sculpted seats. It's the signature blend Caldera owners know asĀ Pure ComfortĀ®, Pure PerformanceĀ®, and Pure StyleĀ®.
The lineup spans three series ā the flagshipĀ UtopiaĀ®Ā hydrotherapy powerhouse, the premium-yet-practicalĀ ParadiseĀ®, and the exceptional-valueĀ VacanzaĀ®Ā ā all engineered for comfort, efficient energy use, and simple maintenance. Genuine Caldera parts and filters are built to the same standard as the spas themselves, so your equipment keeps performing exactly as designed.Ā Come to Caldera. Come to life.
