What You Should Know About Spool Pools

The Ultimate Cross Between Pools and Spas

Person relaxing in spool

Astronaut Images / Getty Images

If you're dreaming of a compact, dual-purpose pool and spa, you might like the spool pool.

What Is a Spool Pool?

A spool pool is a small pool with spa-like features, resembling a large hot tub but with powerful directional jets that create a current against which you can swim. A spool pool is often also called a cocktail pool or plunge pool. A spool pool is half as long as a lap pool, which is designed for full swim laps.

The term "spool," when used in the spa and swimming pool trade, blends the word "spa" and "pool." The term is something of a colloquialism and is generally not used by manufacturers, who usually market these products as "swim spas."

Most often, spools or swim spas are prefabricated above-ground features, but you can also have an in-ground spool pool constructed, which might be a good choice if your yard doesn't have space for a full-sized in-ground pool. Above-ground spool pools can be placed on a large concrete slab or even installed indoors in a basement or large garage. Measuring approximately 10 to 16 feet long and 6 to 8 feet wide, a spool is much smaller than an in-ground swimming pool but at least twice as large as an average spa. Spool pool design ideas may include additional amenities such as built-in seating, ledges, shelves, LED lighting, and waterfalls.

How Spools Work

Spools create currents with directional jets that resemble those used to create the soothing bubbly effect of a standard hot tub. But in a spool, these jets are more powerful and are aimed in a manner that creates a strong directional current in the water, against which you swim or jog. Not all spools are made for exercise—some are designed as small pools that also function as hot tubs. Because you can adjust the temperature, even an outdoor spool might be usable in mild winters.

One of the more popular brands is the Michael Phelps Signature Swim Spa (also known as MP Signature) by Master Spas. This line offers several models with water capacities that range from about 2,000 to 2,400 gallons. These spools have two sections: an isolated sitting section for spa relaxation and a larger swim chamber that is 50 inches deep. Overall sizes range from about 8 by 18 feet to 8 by 20 feet. While some swim spas use the same type of air jets found in standard spas, this line creates a current through the use of a propeller design, which makes for a more realistic current. These spools also have standard jets to enhance the relaxation function.

Working Out in a Spool

Unlike a swimming pool, a spool comes equipped with jets that create a current against which you swim. This resistance allows you to get a great workout in a relatively small amount of space as you swim in place. When using a swim spa as a pool for exercise, the temperature should be kept fairly low, as it gets uncomfortable and can make you tire more easily if you're doing laps in a warm body of water. With this in mind, you might want to first use the spool for exercise purposes with a lower water temperature and then heat it later in the day or evening to relax tired muscles in warm, therapeutic water.

Some models include a partition that makes it possible for one person to use the swim spa as a hot tub, while another person swims laps in a cooler section of the spool.

Advantages and Disadvantages

Spools offer some of the same advantages that swimming pools and hot tubs have, but they also come with some disadvantages.

  • Can be installed indoors

  • Can be used year-round in mild climates; adjustable temperature

  • Can be used as spa, pool, or both

  • More affordable and easier to install and maintain than full-sized pool

  • Can offer a great workout

  • Ideal for small or odd-shaped backyards

  • May add less real-estate value than a full-sized pool

  • Zoning ordinances may require fencing if outdoors

  • Heating and electrical costs can be pricey in colder climates

  • Current may feel uncomfortable

  • Only fits one or two people at a time

  • Can't swim full laps like in a lap or traditional pool

Spool Pool Costs

The lowest you can expect to pay for a fully functional swim spa is about $10,000 for a smaller model or well over $30,000 for a higher-end model with separate spa and swim areas. For example, the largest of the Michael Phelps line of spools made by Master Spa costs about $25,000, though this does not include installation costs or any of the ongoing maintenance expenses. It's not uncommon for a homeowner to spend $50,000 on a fiberglass or acrylic swim spa, including delivery, installation, and setup.

National figures show that the average price paid for a medium-sized prefabricated swim spa is around $22,000, including installation costs. Still, compared to the roughly $60,000 cost for a full-sized fiberglass or vinyl in-ground swimming pool, a spool pool is worth it, considering how it combines the advantages of a swimming pool and a spa in one space-saving water feature.

You can buy a builder's spool pool kit and have it installed by a pool installation company. Contact local pool building companies to see if they offer spool pool design ideas and/or kit installation services.

Before Making a Commitment

While a spool, or swim spa, sounds like the best of both worlds, it's not for everyone. Take one for a "test drive" at a friend or family member's house, or try one out at a local spa dealer before buying one. Make sure the "current" is acceptable—not like the unpleasant blast of a pressure washer or fire hose.

In doing your research, you may find out that you can't live without a full-sized swimming pool in which to swim laps or entertain a large crowd. Alternatively, you may find that all you want is a hot tub that will allow you to receive a nice hot soak and massaging jets targeted on your sore muscles a few times a week. Like anything, it takes time and consideration before taking the plunge and becoming a proud spool pool owner.

Article Sources
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  1. What's A Safe Swimming Temperature? U.S. Masters Swimming Association.

  2. How Much Does a Cocktail Pool Cost? Home Advisor.