At Thunderbird Pools, we believe that every backyard, no matter the size, should be a sanctuary where your family makes memories that last a lifetime. For homeowners in the Phoenix Valley with smaller lots or a desire for a more intimate retreat, the inground spool has become an ideal solution. A clever hybrid of a spa and a pool, a spool offers the therapeutic benefits of a hot tub with enough space to lounge and splash, making it a perfect fit for backyards throughout the Phoenix Metro area.
If you have ever found yourself debating between a full-sized swimming pool and a dedicated hot tub, a luxurious spool pool is the perfect middle ground. Essentially, a spool is a scaled-down pool, typically measuring around 10 to 15 feet in length.

While they have a smaller footprint, they are engineered with high-end features that allow them to function as both a refreshing dipping pool during a 110-degree July day and a heated, jetted spa for a chilly January evening. As a family-owned builder with over 20 years of experience, we build our spools with the same permanent materials and structural integrity as our full-sized projects, ensuring they become a seamless, integrated part of your outdoor living space.
Navigating the world of small pools can be confusing, as many of these terms overlap. However, there are subtle differences in how each is used:
- Cold Plunge Pools: These are deeper pools designed for cold-water therapy. With the addition of a chiller, we can bring the water temperature down to as low as 40 degrees, creating a true cold plunge experience.
- Dipping Pools: Usually the smallest and shallowest option, these are designed for sitting or standing in waist-deep water to stay cool while enjoying a drink or conversation.
- Cocktail Pools: These are designed specifically for entertaining. They usually feature extensive bench seating and are shallower, allowing guests to stand and socialize comfortably.
- Spools: The "Spa-Pool" hybrid is the most versatile. While a plunge or dipping pool might stay cool year-round, a spool is outfitted with powerful heaters and therapeutic jets, giving you the ability to transform the entire body of water into a giant hot tub at a moment's notice.
Backyard spools require a unique approach to design because every square foot of the interior is utilized for comfort. We focus on maximizing the social aspect of these builds, incorporating features that make the space feel like a private resort.
Because we prioritize quality and durability, we utilize shotcrete for the shell of every spool we build. This ensures the structure can withstand Arizona’s expansive soils and intense heat. We also partner with industry leaders like Hayward to provide energy-efficient heating and filtration systems. Because a spool has a smaller volume of water than a traditional pool, these advanced heaters can bring the water to spa temperatures much faster, allowing you to decide on a whim to enjoy a hot soak under the Arizona stars.
An inground spool is a significant investment that adds undeniable value and beauty to your home without overwhelming your yard. At Thunderbird Pools, our mission is to provide the expert craftsmanship and honest guidance necessary to help you decide which small-pool style is right for your lifestyle. We are here to help you navigate the engineering and design process, ensuring the final result is a quality retreat where your family can thrive for decades to come.
Because a spool requires the same high-quality pumps, heaters, and shotcrete as a full-sized pool, along with the added cost of specialized spa jets, the price is often comparable to a traditional pool. In the Phoenix area, you can generally expect a custom spool to start at around $65,000 and go up from there, depending on the complexity of the masonry and equipment.
Yes! This is the primary reason many of our neighbors choose this design. In the summer, you can keep the heater off and use it as a cocktail pool to stay cool. In the winter, the smaller water volume allows the heater to raise the temperature quickly, transforming the pool into a massive hot tub.
Generally, yes. There is less water to treat and a smaller surface area to skim, which reduces chemical demands. However, because spools are often kept at higher temperatures, it is important to stay consistent with your pH balancing to keep the water pristine. We provide every client with a simple maintenance plan to ensure their sanctuary remains stress-free.
The construction process follows the same rigorous steps as a traditional pool, including excavation, steel reinforcement, and shotcrete. Because we treat every project with the care of a family-owned business, we don't cut corners on the engineering. You can typically expect the process to take several months from the time permits are approved to your first fill day.

Thunderbird has been designing and building custom pools and spools throughout the Phoenix Metropolitan area for more than two decades. With over 20 years of experience, our team can help you determine the ideal combination of size, shape, and features to create a small‑space retreat that fits your lifestyle and your budget. Whether you're exploring a versatile spool, a cold plunge, or another compact pool design, contact us today to start bringing your backyard vision to life.
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