For years I’ve been asked what the difference is between a hot tub and a spa. Are they two totally different things? Can the two names have the same meaning? Are they the same thing or not?
A hot tub is defined as a manufactured small pool that holds heated water for soaking, massage, and overall relaxation. The first hot tubs were round and made of wood. They usually had an external heater such as natural gas or wood fire. Over many years of evolution, most tubs now are made of plastic or acrylic over a fiberglass shell. These hot tubs are usually heated by an electric heater that is under the shell. Most hot tubs you would find today would be considered portable hot tubs. This means that all the components of the hot tub are contained internally in the tub.
The other word, spa, has several meanings. It can be used to describe a high-end hotel, a resort with mineral springs, or a commercial establishment providing facilities devoted especially to health, fitness, weight loss, beauty, and relaxation. The most popular use of the word spa, as defined by Merriam-Webster dictionary, is a hot tub with a whirlpool device.
If you combine the descriptions of hot tubs and spas, you come up with a small manufactured pool that holds hot water and has pumps to power jets that create whirlpool action for message and relaxation. This describes almost every hot tub or spa at any hot tub or spa store. Wikipedia gives an alternate definition for the word spa– a hot tub in United States usage. So in the United States, people, and even manufacturers, use both terms for the same meaning. Hot tub or spa, it doesn’t matter. If you’re referring to hot water, everyone will know what you’re talking about.