Relax amid swirling waters...in summer and winter! If you're toying with the idea of purchasing a hot tub for your backyard, there are a few things you should know before you jump in.

WHAT TO CONSIDER
Advantages
Hot tubs have become increasingly popular -- with good reason. First, unlike swimming pools, they can be used year-round, thus giving you a better return on your investment. What's more, because a hot tub doesn’t have to be closed for the winter (unless you're unable to maintain it), you'll save on pool starter and closing kits. There are other advantages. A hot tub takes up less space and requires less maintenance than a swimming pool, and it can easily be moved. As well, a permit isn't required to install one, nor is it necessary to build a fence around it. All you have to do is lock up the cover when the hot tub is not in use. And last, but certainly not least, the hot tub is a haven of peace: It promotes relaxation, offers all of the benefits of hydrotherapy and, with its therapeutic qualities, it can be a boon to people with back pain and sore muscles.

Disadvantages
Conversely, a hot tub will drive up your winter hydro bill by one to three dollars per day, and the children won’t have as much fun as they would in a swimming pool. Also, its hot water (between 35°C and 40°C) will offer no relief during a heat wave. That’s not even mentioning the cost: between $5,000 and $15,000 compared to just over $3,000 for an above-ground swimming pool measuring 21 feet in diameter.

Size
Hot tubs come in a variety of sizes designed to accommodate anywhere from 2 to 10 people. Before selecting a size, though, it's important to consider the space you have available and to determine where you intend to place the unit. As well, consult your municipality and your insurer to find out how much distance is required between the hot tub and both the house and the edge of the property.

Then you'll want to think about how much space you need to be comfortable. How many people will be using it at the same time? Do you intend to soak solo, with a significant other, as a family or with friends? A word of advice: You're better off basing your choice on its actual use than its potential use. In general, a five-person unit will suffice to accommodate a family and, occasionally, friends.

Your needs
Choose a hot tub that suits your tastes, needs and lifestyle. Will it be used to socialize, relax and re-energize or soothe aching muscles? In the first two instances, a 20-jet hot tub should be more than enough -- better yet, it won’t be too loud. In the latter case, a minimum of 30 jets is needed to massage your body from the tips of your toes to the nape of your neck. If you suffer from back pain, opt for one with jets pointed toward the length of the spine. Note that pregnant women and people with heart conditions are advised to avoid hot tubs. The number of seats should also be taken into account. In general, a five- or six-person model is recommended. Each place is outfitted with jets meant to massage specific parts of the body, and the user will have to sit in every place to obtain a total body massage. A four-person hot tub features fewer jets, and as a result its massage won't be quite as complete.

THE COMPONENTS
To ensure that you're purchasing a quality product, pay special attention to each of the following components.

1 The shell
Made of acrylic, fibreglass and resin, a quality shell must be at least five millimetres thick, and the corners and other strategic areas -- the entire bottom, the seat bottoms and the area underneath the edges -- should be reinforced with fibreglass. To be certain that this is the case, ask to view a slice of the material and verify the minimum thickness. Finishes are available in matte, pearl or a granite-like texture. Choose whichever you prefer, but bear in mind that scratches won't show as much on a granite-like or pearl finish. Some manufacturers use Microban technology to prevent the spread of bacteria responsible for odours and stains. However, while this technology preserves the shiny finish and doesn’t entail additional costs, it does not necessarily guarantee quality.

2 Insulation
Given the rigours of our climate, the hot tub should feature top-quality insulation. Otherwise, your hydro bill will be sky-high, and in the event of a power outage it will quickly cool down, increasing the likelihood of damage. There are two types of insulation procedures: The tub can be completely covered with insulating foam, or it can be insulated with a combination of polyurethane foam and vapour barrier. In either case, all four panels must be insulated. According to retailers, the two procedures are equally effective, though the second provides easier access to the plumbing in case of a breakdown, which may save time and money.

3 The skirt
A hot tub is generally surrounded by a wooden structure meant to level it and support the shell. This structure also houses the skirt, an outer layer made of cedar or resin. Cedar is rot-proof, though it turns slightly grey over time; this in no way affects its durability, but some people find the look displeasing. To preserve the skirt’s colour, therefore, treatment with a water-repellent product is suggested. To reduce maintenance time, opt for a wood-imitation resin skirt, which is comparable in price to cedar. An important point: The various sections of the skirt must be removable. If a part breaks, you’ll want to be able to get to it easily by removing the appropriate panel.

4 The pump
The pump serves to control the power of the jets. For a quick dip in low turbulence, a single pump is more than enough. For a therapeutic massage, however, two pumps are necessary, and a third may be added for a more vigorous massage. Current models have a power output ranging from 2 to 6.5 horsepower. The more jets a hot tub features, the more powerful its pumps must be. The pumps also serve to oxygenate the water by gently circulating it 24 hours a day. Several times each day, the hot tub should run at high speed for a minute to flush out the pipes.

5 Accessories
All hot tubs are equipped with at least one light and a control panel. (Make sure that the panel is easy to reach once you’re seated in the tub.) Most control systems are digital and allow the user to regulate the water temperature to within one degree. Some accessories are highly recommended -- like the resin step for easy entry and exit – while others are mandatory, like the circuit breaker, which prevents users from being electrocuted in the event of lightning orcurrent variation. Manufacturers’ extras may include a sound system, a DVD player or an illuminated cascade. Before you decide to purchase accessories (which increase the price tag substantially), ask yourself whether you’ll put them to good use. Watching a film in a hot tub, for example, is pointless since the noise generated by the jets will muffle the sound of voices. And while relaxing in the hot tub and listening to music is an option, you can forget about having a conversation.

6 The cover
It plays an important role by protecting water from debris, maintaining water temperature and preventing children from entering the hot tub. To ensure that the spa stays insulated and promote runoff when it rains, the cover must be domed. It must also be lockable for security reasons. The thickest part should measure at least 10 centimetres and the thinnest at least 7.5 centimetres, strong enough to support the weight of a young child. Also make sure that the leatherette is flexible enough that it doesn’t crack or damage when exposed to variations in temperature. Finally, a handle is always useful to open and close the cover and to carry it to a storage area when it isn’t being used.

7 Jets
Two main types of jets are available: hydrojets and aerojets, and they are usually combined. Hydrojets project a mixture of air and water, creating the main massage effect. The larger the hydrojets are, the softer your massage will be. Aerojets, for their part, emit thousands of tiny air bubbles, thus contributing to a feeling of weightlessness and providing a softer massage. Nozzles (water outlets) are available in several shapes, making it possible to vary the angle and movement of the jet, depending on the kind of effect (relaxing or invigorating) you want to achieve. Some nozzles are interchangeable, a potentially interesting option.

8 Filtration
The water from a hot tub is the ideal environment for the proliferation of bacteria, hence the importance of the filtration system. In a four-person hot tub, the antibacterial filter cartridge must be capable of cleaning a surface spanning a minimum of seven square metres. Owners are advised to buy a second filter (for purposes of rotation during cleaning) and closely follow the manufacturer’s cleaning instructions. Cartridges last roughly one year and cost approximately $100. Also important is making sure that the skimmer door assembly measures at least 25 centimetres for effective filtration and proper filter collection. Many hot tubs also feature an ozonizer, which naturally sterilizes and disinfects the water, thus reducing the use of maintenance products. The ozonizer is not an absolute must, however.

9 The water heater
To be effective, the electric water heater must have an output of 5.5 kilowatts. Two types of electric water heaters are available: those with an element inside the water and those with an element that does not come into contact with the water. According to experts, the latter offers the best quality, as there is no risk of the element being damaged by the water. Also, corrosion-resistant titanium water heaters are considered a good option.

The comfort
The same seat will not offer the same comfort to someone who is six feet tall as it does to someone who is five feet tall. For this reason, shells with seats at varying heights are preferable. Some hot tubs feature jets that can be adjusted to meet individual needs. To choose a hot tub that’s comfortable and best suited to you, first try each seat using the demonstration models available in-store. If you find yourself hesitating between two or three models, ask the dealer for a test run -- yep, in a bathing suit, in the water. In doing so, you’ll be able to tell if the jets can be adjusted to the required intensity and positioned in such a way as to massage your muscles and not your bones or your spine.

The retailer
A hot tub is a long-term investment (good for about 20 years), and there’s no reason you shouldn’t shop around as you would for a car, visiting several retailers to compare products and prices. Err in favour of retailers who’ve been in business for a long time and offer good after-sales service, and for personalized service give priority to specialized stores. Also check if the retailer offers technical services and is open year-round. In the event of a breakdown during winter, you’ll be glad that you’re able to reach a qualified maintenance person.

Cost and warranty
Expect to pay roughly $5,000 for a basic hot tub with a limited number of jets and the basic accessories. More sophisticated, superior-quality models start at $7,500. Before you decide on a model, carefully read the warranty on each component (they sometimes differ) and take the time to read all related documents, particularly the exclusions. Solid warranties on parts and especially labour are a good gauge of quality. Some retailers are pricier than others but offer a better warranty on labour.

Installation
A hot tub should be installed close to the house for quick access (approximately three metres), especially when it’s below zero! A location sheltered from the wind (so the water won’t freeze) and a fair distance from trees (to take advantage of solar energy) is considered optimal. Also see to it that the desired location is able to support the weight of the hot tub and its occupants. (A tub with four occupants will weigh an average of more than 2,700 kilograms.) The ideal is to build it on a concrete slab. Interlocking stone and tile may also suffice, provided that they sit on a compacted stone dust surface measuring a minimum depth of 25 centimetres. The electrical hookup must be carried out by a master electrician. Once this is done, all that’s left to do is to fill the hot tub using the garden hose, pour in the starter kit (usually provided by the retailer) and enjoy!

Maintenance
Chemically formulated products must be added periodically to preserve water quality, following the instructions provided. In general, two options are available: weekly-use bromine and daily-use lithium. Each disinfects the water, though bromine has the advantage of being soft on sensitive skin, while lithium is odourless and costs a little less. Regular water analysis is also a must. Ideally, the retailer should check it once a month (many offer this service free of charge), or you can check it yourself and confirm the results with the retailer. Other various components -- the filtration system and the shell -- also have to be maintained, in keeping with the manufacturer’s care instructions, which should be read carefully.