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Educational Consumer Tips

Buying a Hot Tub or Spa

Author: Rachel Gelb
Category: Health

Hot Tub vs. Spas

Before deciding on a spa or hot tub, find out about the options available to you. Spas and hot tubs are similar in that both use swirling water and therapeutic heat to soak and massage sore muscles and painful joints. The difference between the two is simple:


  • In hot tubs, the bubbling water comes from under and around the seats.


  • In most spas, the bubbling water comes up directly through the floor and seats.
While the benefits derived from a hot tub or spa are similar, their construction and appearance are quite different.

The Hot Tub

The original hot tub was an old wooden wine cask. Today, hot tubs are constructed in a similar fashion with constant soaking of the wood keeping the tub watertight without use of nails. The most popular wood used in the tub construction is redwood. Vertical grained all-heart redwood is strong, watertight, aesthetically pleasing and if properly maintained, will last for 15 years.

Other durable and usable hardwoods include cedar, cypress, oak and teak. The main characteristics that differentiate these woods are:


  • Redwood is extremely resistant to decay, does not splinter, and swells easily to watertightness.
  • Cedar comes close to resistant on all counts, except it may not be as long-lasting.
  • Cypress is very durable and resistant to alkalis, acids and other chemicals.
  • Oak, a hardwood, is extremely durable if maintained properly.
  • Teak is the most durable and decay-resistant of all, and has a natural oily smoothness. However, high price and availability may present drawbacks.

Hot tubs are usually four feet deep. While most are five to six feet in diameter, they can be as small as 3 1/2 feet in diameter or as long as 12 feet or more. A standard 5' x 4' tub holds 500 gallons of water and is generally comfortable for four adults. A 6' x 4' tub holds 700 gallons of water and is generally comfortable for six adults.

Prices of a redwood or cypress tub alone can range between $1,500 and $1,900. Cedar tubs cost about $200 less, and oak can cost almost double. Teak is more expensive with prices depending on location and availability of wood.

With the additional expenses of support equipment and installation, you can expect a wooden hot tub to cost between $4,000 and $6,000.

While it is possible to cut cost by using wood of lesser quality than heartwoods, you risk the possibility of splintering and leaks.

The Spa

Various materials ranging from concrete to hard plastics have been used in constructing spas. Each material has its own characteristics in terms of spa shape, size, color and durability.

Gunite (air-blown concrete)--
Traditional, older spas and those built adjacent to swimming pools are frequently made of cement or gunite. In gunite construction, a webbing of steel reinforcing rods is used to conform to almost any shape or size of the spa. Most concrete and gunite spas have a band of ceramic tile rimming the spa at the water line to make cleaning easier. Some are completely lined with tile. The price of concrete and gunite spas depends on the size, location and difficulty of installation.

Keep in mind that concrete and gunite spas must be custom designed and individually constructed and therefore are more time consuming and expensive to build. Also, note that installation is almost always included in the total price quoted by the contractor.

Used mainly as a backing to strengthen acrylic and gelcoat spas, fiberglass can be either bonded or sprayed on the back of molded acrylic or gelcoat spa shells.

A polymer resin sprayed onto a spa shell is allowed to harden then removed from the shell and sprayed with fiberglass for strength. Gelcoat fiberglass spas cost slightly less than acrylic fiberglass but are considered less durable. Gelcoat generally requires more routine maintenance and often needs resurfacing after about five years.

Dense and non-porous, acrylic constructed spas provide a very hard, scratch-resistant surface that maintains its color and faith. Acrylic is available in various colors. However, because acrylic is not strong enough to stand on its own, it also requires fiberglass reinforcement.

Tough, sturdy and resistant to sun and chemical damages, and extreme temperatures, thermoplastic spas are noted for their strength, resistance to scratching and retention of colors. They are thicker and more resilient than acrylic and do not require fiberglass reinforcement. These plastics are also available in many colors as well as simulated marble.

Portable Spas
An addition to the spa industry is the portable spa. Constructed of fiberglass, often with an outer skirt of wood or other material, the portable model has heating, electrical, filtration and pump equipment within a self-contained unit.

The portable spa can be installed in or out of doors, and usually fits through a standard doorway. A key advantage of the portable is that it can be taken with you when you move.

Portable spas cost from $3,000 to $4,500. This includes the cost of the spa and support equipment. The cost of installation is either free or nominal.

Selecting a Dealer
If you are seriously thinking of buying a hot tub or spa, check with friends, colleagues or neighbors who own or have used them. Ask for their impressions and whether you can try out their facilities. Get a recommendation for a professional hot tub/spa dealer, if possible.

Contact your local Better Business Bureau for a reliability report on any dealer you are considering.

If you live in a condominium, check with your local condo association and get permission in writing before making a commitment to buy. If you live in a detached home, check to ?see what local building ordinances apply.

It is a good idea to locate several dealers and arrange to try out a number of models. Most dealers will be happy to set up a trial of soaking. Ask several dealer to submit a written list of contract specifications.

Each contract should include:

  • Explicit specifications for size, shape and materials to be used in constructing the spa or hot tub, and a detailed description of the equipment, including brand names;
  • Installation date;
  • Completion date with appropriate understanding regarding delays;
  • Written understanding as to your responsibility regarding unexpected cost, such as those resulting from the contractor hitting rock or water, or the moving of utility lines.
  • Schedule of payments, with the last payment tied to the completion of the project,
  • Description of any after care service or periodic check-ups; and a
  • Copy of the warranty indicating what is not covered, and for how long.

You should base your selection of a dealer on all the information you receive, not cost alone.

Financing Arrangements
Some hot tubs and spas are considered a good property investment by banks, and prospective buyers should inquire about available financing arrangements. While some spa and hot tub companies offer financing it is wise to shop around carefully because interest rates usually vary.

The addition of a spa or hot tub will often increase the market value of your home. However, keep in mind that if the addition significantly raises the potential price of your home above that of comparable homes on your neighborhood, the reverse could be true and your home may be harder to sell. In either case, you might consider talking to real estate professional about your plans before proceeding.

Choosing The Hot Tub Or Spa Site
Whether indoors or outdoors, the sitting of a hot tub or spa is a highly personal decision based on your intended use and the existing features of your home and property.

If your home has a scenic view of a secluded grove of trees, for example, you may wish to create a special area in which your hot tub or spa enhances this environment. For an indoor spa, you might have to enlarge an existing room or build an addition. This increases the total cost, but should also add to the value of your home.

If you already own a swimming pool, you may be able to make use of some existing plumbing and heating equipment by locating the tub or spa next to the pool.

As for a portable spa site, remember you can move a portable spa around to suit yourself, as long as the floor, deck or ground can support its weight and utilities are accessible.

Support Equipment
The hot tub/spa support system includes everything required to circulate, filter and heat the water and is often a separate purchase. The system consists of a water pump, filter, water heater, air blower and the plumbing and hardware necessary to hook them up.

The pump circulates the water through the system through hydrotherapy jets, commonly called "hydrojets." The filter helps keep the water clean by removing minute particles of dirt, debris and algae.

An all inclusive package of equipment is called a "skidpack" and may be offered at a special price when the spa of hot tub is purchased. An advantage of buying the skid pack is that the components included are most likely matched for optimal performance. Buying the components individually may result in a mismatching of the equipment's electrical and hydraulic capabilities.

Some general rules to follow are:

  • A one-horsepower pump motor is usually sufficient for a 500-700 gallon spa or hot tub with four hydrojets. A two-speed pump may offer energy-saving potential. The higher speed is for jet action, while the lower speed is for circulating the water. It is generally wise to keep the pump on several hours per day at the lower level to keep the water at a fairly even temperature.


  • There are three types of filters: cartridge, sand and diatomaceous earth (DE). Most home spas and hot tubs use cartridge filters which last one to two years before needing replacement. They do require regular cleaning with a recommended cleaner.

    Larger hot tubs and spas often are equipped with DE or sand filters. While these filters are more efficient than cartridge filters, cleaning either of these is more complicated than cleaning a cartridge filter. In all cases, there are different filter sizes, and the size for your system must be compatible with the pump.


  • Heaters are usually powered by either electricity or fossil fuels. Fossil fuel systems (burning either natural gas, oil or propane gas) heat the water faster which may be a consideration for a large spa or hot tub, or one located in a cold climate.

    The size of the heater selected depends on how much water is to be heated and how quickly. For example, a 70,000 BTU heater can raise the water temperature in a 500-gallon spa by 10 degrees Fahrenheit in 51 minutes. A 225,000 BTU unit could do the same job in 14 minutes.

    Keep in mind that the smaller heater may not necessarily be more energy-efficient since it must run that much longer. Less popular alternative heating systems include solar, wood or coal burning heaters. Your dealer should be able to answer questions about these systems.


  • Air blowers, which produce tiny air bubbles, and hydrojets, which produce aerated streams of water, must be the correct size for your spa of hot tub. While they are generally maintenance-free (requiring cleaning only when the tub or spa is emptied). they must be installed exactly as specified by the manufacturer.

Water Treatment and Chemicals
When you are looking at a spa or hot tub and support equipment, you should be sure to find out about water treatment requirements recommended by the manufacturer or dealer. A water quality test kit is a necessity. Because warm water aids in the growth of bacteria and algae, owners should regularly test the water. A test kit can determine: pH level (acidity); total alkalinity; and calcium hardness.

Spa and hot tub water must have the correct balance of these elements. Unbalanced water can irritate eyes, corrode the equipment and leave mineral deposits.

Among the chemicals recommended by manufacturers are chlorine, bromine, sodium bicarbonate and sodium bisulfate. Check with your dealer or the manufacturer for specific instructions on the use of chemicals for testing the water.

Optional Accessories
Optional accessories which will enhance the operation of your spa or hot tub include a variety of items. The most important of these is a skimmer, particularly if your spa or hot tub is located outside or used frequently.

Consider that five people in a 500-700 gallon spa or hot tub is equivalent to approximately 250 people using an average size swimming pool (250,000 gallons). The natural residue of body oils and dirt, not to mention leaves and other debris if the spa or tub is located outdoors, can easily overburden the filtering system. A skimmer removes leaves, oils and other pollutants from the surface of the water.

Second in importance to a skimmer is a water purification system to supplement the filtering and chemical treatment. This can keep the water free of microscopic impurities. Purifying systems leave no residue, remove most odors and may also reduce the amount of disinfectant required for proper water treatment. However, a purification system should not be used in place of chemical treatment.

One accessory which most spa or tub owners eventually acquire is a cover. Whether made of fiberglass, plastic, wood, canvas or another material, a cover can help keep children out, prevent debris from blowing into the water, prevent some heat from escaping and reduce evaporation.

For outside spas or tubs located in cold climates, a freeze-protection kit that insulates pipes and support equipment is essential.

Safety Tips To Remember
While many claims have been made about the therapeutic benefits of warm water soaking, some overstate the truth. What is known is that warm water dilates blood vessels and, in turn, increases blood flow to muscle tissue. This can reduce pain in sore muscles and may make it easier for the heart to pump blood to those areas.

Experts promoting the safe use of spas, hot tubs, and swimming pools, caution that soaking in warm water may pose a number of potential dangers, and issue the following warnings:


  • Persons with heart disease, diabetes, high or low blood pressure or any serious illness, pregnant women, or anyone with doubts about their physical well-being, should not enter a spa or hot tub without prior consultation with their physician.


  • High water temperatures can elevate your body temperature and the temperature of your internal organs beyond safe limits. Maximum water temperature should never exceed 104 F (40 C).


  • Soaking too long makes some people nauseated, dizzy light-headed or faint. Do not soak for more than 15 minutes at one sitting in 104 F water. Check the water temperature before and while in the tub or spa.


  • Never use the spa or hot tub when alone.


  • Never use a spa or hot tub while under the influence of alcohol.


  • Never use a hot tub or spa when taking such prescription drugs as anticoagulants, antihistamines, tranquilizers, etc.


  • People with any type of infection, open sore or wound should not use the spa or hot tub.


  • Before entering the water, check it for cloudiness, foaming or a strong chlorine smell. Soaking in dirty water may result in a skin rash. Always shower with soap and water before and after using a spa or hot tub.


  • Never adjust or touch equipment, such as pumps, heaters or electrical appliances while in the spa or hot tub, unless such use is indicated by the manufacturer.


  • Enter the water slowly and cautiously. Be careful of your footing and allow your body to gradually get use to the water temperature. Leave slowly as well, because your leg muscles may be sufficiently relaxed to make you a bit unsteady, and you might become lightheaded.


  • Never allow children to use the hot tub of spa, unsupervised. If young children will be using your spa or hot tub, explain to them that they cannot dive or jump into it under any circumstances.

About the Author: Rachel Gelb is Communications and Marketing Manager for BBB serving Eastern Massachusetts, Maine, Rhode Island and Vermont. Find Rachel on Google +.

Questions and Comments

Question Submitted 5/10/2013

How are four winds spas rated

BBB's Answer:

You can find that information on
Click Check out a Company
Enter in the business name
If BBB has information on the business you will be able to click to see the Business Review. 

Comment Submitted 5/27/2013

How can I have a hot tub/spa pit in the ground?

Comment Submitted 9/24/2013

Can a spa be used in the summer as merely a swimming pool to cool off by not having it heated? Or, does a spa or hot tub always have to have high heated temps?

Comment Submitted 6/18/2014

What is the best NAME BRAND of hot tub/spa tub on the market today?

Comment Submitted 8/10/2014

whats a good brand that you would suggest?

Comment Submitted 8/25/2014

After 10 years of owning a Hot Spring portable hot tub it started leaking in 3,4,& 5 places. Very disappointed in this brand, which was rated very good

Comment Submitted 11/14/2014

im considering a small Jacuzzi or Bullfrog. Which has better performance and reliability, and are there other brands that are of equal or batter quality?

Question Submitted 3/14/2015

Am looking into either buying a hot tub or outdoor spa to take the place of a small pool which I am filling in. I am asking the same question- Can a spa be used in the summer as merely a swimming pool to cool off by not having it heated? Or, does a spa or hot tub always have to have high heated temps? Also any recommendations on where to buy? thanks*******

BBB's Answer:

You can search for dealers in BBB's Accredited Business Directory. See the link below:

I would ask any business to shop your specific questions about whether or not the spa can be used as a pool.

Question Submitted 5/23/2015

Can an indoor jacuzzi tub be modified for outdoor use?

BBB's Answer:

It would depend on the tub. I would ask that question of the dealer.

Question Submitted 10/5/2015

Legally, do I have to put a fence or enclosure around the Tub to prevent children from getting into it on their own?

BBB's Answer:

This article may assist you

This is an application for a permit - that may also provide helpful information.

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Views expressed on this page are those of the individual author and do not necessarily reflect the views of Better Business Bureau.

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