I. Introduction

    Occasionally I am asked what difference there is between a spa and a hot tub. Today the words are used interchangeably. In the past, the term 'spa' referred to a place you would go to visit natural mineral springs. To the west of Memphis, Tennessee there is a town called Hot Springs, Arkansas (just outside Little Rock) that still has spas in operation. The term 'hot tub' was applied to wooden tubs that people owned in their homes.

    Today both 'spa' and 'hot tub' are used to refer to all the kinds of hot water baths available. The term 'whirlpool bath' is usually reserved for the smaller jetted units found in modern bathrooms. We'll cover each of these in turn. Throughout this website I use the words 'spa' and 'hot tub' to mean the same thing, and I alternate their use to avoid boring repetition.

II. Features

    The thing all spas and hot tubs have in common is jetted hot water. The heater can be electric or gas fired (propane or natural). Sometimes spas are heated passively by the sun or the pump's operation. Indoor whirlpool baths are filled with hot water before each use with hot water from the home's hot water heater. Once filled, the jet pump is turned on.

    Spas use electric pumps to jet the water into the tub. A common feature is to have a low speed and a high speed jet action. This can be done in two ways. There can be two pumps, or one pump that has two speeds.

    In the old days, jets were simple openings through which the water flowed. Now there are jets that inject air, jets that spin or pulsate, jets that spray mist, jets that alternate in a pattern, jets of all shapes, sizes and description. The idea is to provide an enjoyable, stimulating, relaxing, sensual and therapeutic experience.

    Aside from jetted water, there are other features a hot tub may have. Air blowers are a common addition. An electric blower is used to force air into the tub through a series of tiny holes usually located in the seating area. This adds a bubbling effect while cooling down the water.

    Lighting provides a nice atmosphere and sets the mood, as well as adding a measure of safety. Light sources can be incandescent, halogen, lens type, fiber optics, you name it.

    There are many other features a hot tub may have. I'll list a few here without going into detail. Ozonators can be added to help reduce the amount of chemical disinfectant needed. Timers allow you to operate the spa in a way that fits your lifestyle and conserves energy. Fancy control pads provide hi-tech ways to program the various functions a spa may have. Spa covers keep heat in and debris out. 

    Below is a round-up of the various types of spas based on their construction methods.

III. Types of Spas

A. Concrete Spa

    Concrete spas are built using the same materials as concrete swimming pools. In fact many are attached to swimming pools and sometimes spill over into them. But they can also be self contained. Made of concrete and steel reinforcement, they can have a plaster or tile finish. The equipment (pumps, filter, heater, blower) are normally located feet or even yards away.

    Concrete spas are custom built on site to the customer's specifications. They are meant to last a lifetime and often last several lifetimes.

B. Fiberglass Spa 

    Fiberglass spas are often called portable spas because they are self-contained and can be easily moved about. While most are enclosed in a cabinet and meant to be above ground, some spas do not have cabinets and can be sunken into the ground. Wooden decks are often built around portable spas to make it easier to enter and exit.

    Fiberglass spas get their name from the fact that fiberglass is the material that gives the spa structure. The fiberglass may be 1/8" to 1/4" thick. The acrylic surface is laminated on top of the fiberglass and is typically less than 1/16" thick.

    Acrylic is plastic. When I was a kid anything made of plastic was considered cheap. Not anymore. You can do things with plastic that you can't do with other materials, and plastic lasts a long time. Plastic stands up to hot water extremely well and the modern finishes are beautiful and stylish.

C. Wooden Spa

    Wooden spas are not as common as they once were. But they are still made and still provide an enjoyable hot tub experience. They require more maintenance than fiberglass spas and quality wood is not cheap by any means. They tend not to have as many bells and whistles as their fiberglass counterparts, but people who own them love them.

D. Whirlpool Baths

    Whirlpool baths are bathtubs with jets. They have two advantages over other types of spas. First, they are conveniently located in the bathroom so you don't have to go outside to use them. Second, they are simple to maintain since they are filled with hot water and emptied after each use.

    The downside is that they typically only accommodate one or two people, so hot tub parties are out. And they have none of the other features that a full fledged hot tub will have, like a blower and a light. Still, they are so easy to use that their popularity is growing, especially since many homebuilders are installing them in new homes.

IV. Conclusion

    People seem to fall into two categories. Those who love hot tubs, and those who don't. Personally, I have been in a hot tub four times in my life and wondered what was the big deal. So I guess I'm not a hot tub lover. Several times a year we get calls to remove a hot tub from a person's home. Either they bought the home and it was there, or they haven't used it in years and want it removed. They say, 'If you can get it out of here, you can have it." So we take the tub, fix it up, and find it a new home.

    My customers who are hot tub lovers love their tubs for many reasons. Some are athletes who need the therapeutic action of jetted hot water. Some are older people whose bodies also respond to hot water. Some are romantics who like to share their hot tubs with loved ones. Some are involved in active high stress lifestyles who say their tubs help them to unwind. Some are college age guys who say their dates love to get in and take their tops off. Some are very ill and their spa gives them much needed relief from pain. The reasons for owning a spa are as varied as the spa owners themselves. 

    Unlike swimming pools, spas are very personal to their owners. Often a family will move their spa all the way across the country to their new home, rather than leave it behind and buy a new one. Most people maintain their spa themselves, becoming experts in its operation and care. Some people use them exclusively in the winter, while others only use them in the summer, still others keep theirs in use all year long.

    In my business, I respect all the different reasons people love their hot tubs. Our job is to repair them when they break down so people can get back to their routine. We also teach people how to take care of their spas in a simple way. And that is what this website is designed to do. Spa chemical balancing is the most confusing topic and we try make it simple so people can learn to do it themselves.

Return to Spa Main Page.