The words “hot tub”, “spa”, and “jetted bathtub” are often used interchangeably to describe three very different products - in-ground spas, above-ground portable spas also known as hot tubs, and jetted bathtubs. Allow us to provide some clarification on the difference and nomenclature.
In-ground Spa
Not to be confused with a day spa, the term spa is often used to describe an in-ground spa. An in-ground spa is a body of water built into the ground, much like an in-ground pool. In residential settings, in-ground spas are usually built attached to the in-ground pool and are also what you are most likely to see at a hotel or gym. In-ground spas typically have a bench seat and a few jets built-in around the perimeter. They take a long time to heat up, and require a significant amount of energy to keep hot.
Hot Tub
Hot tub is typically used to refer to an above-ground portable spa. A hot tub or portable spa is a completely self-contained vessel. All of the plumbing, as well as the electrical control system and other components, are built inside the hot tub cabinet. This means that there is no plumbing required. A hot tub is filled with a garden hose, can be drained anytime, and can even be relocated to a new home if you move.
One of the best thing about hot tubs is their ability to hold a set temperature. Thanks to advancements in technology, you can set a selected temperature and expect your hot tub to be hot and ready to use anytime you are. There is no need to wait for the hot tub to heat up.
Hot tubs can range from very simple designs with a few jets, to intricate acrylic shells with an extremely high jet count. Hot tubs today have come a long way from the round redwood vessels of the past, and generally offer a much better experience than in-ground spas because they are more comfortable, more energy efficient, easier to care for, and provide better massage.
Jetted Bathtub
Much like Kleenex® and Xerox®, Jacuzzi® is a brand name that is sometimes incorrectly used as a generic term. The word "jacuzzi" is often heard when referring to an in-ground spa, a jetted bathtub, or an above ground portable spa or hot tub. The Jacuzzi brothers invented the first underwater jet, originally used in bathtubs, and called it a Jacuzzi jet. The Jacuzzi® brand today is a trademark for bathtubs as well as portable hot tubs - but since Jacuzzi® is a brand name, it's a good thing to remember that not every hot tub or jetted bathtub is a Jacuzzi® product.