DISSERTATION

DISSERTATIONNAVYA RAOHASTECHI.D III/13

TOPIC: SWIMMING POOL

TOPICS INTRODUCTION HISTORY DIMENSIONS SHAPES INFINITY POOLS PERIMETER-OVERFLOW POOLS CLASSIC RECTANGLE AND LAP POOLS FREEFORM POOLS GEOMETRIC POOLS CUSTOM POOLS KIDNEY SHAPED POOLS GRECIAN AND ROMAN POOLS TYPES PRIVATE POOLS CHILDREN POOLS PUBLIC POOLS COMPETITION POOLS EXERCISE POOLS HOT TUBS AND SPA POOLS OCEAN POOLS INFINITY POOLS NATURAL POOLS AND PONDS ZERO ENTRY POOLS HOW DOES POOL WORK POOL BASICS REQUIREMENTS CONSTRUCTION ABOVE GROUND POOLS FILTER GLASS POOLS VINYL -LINED POOLS GUNITE POOLS POURED CONCRETE POOLS POOL DRAIN SYSTEM POOL PUMP SYSTEM POOL FILTERS POOL CHEMICALS POOL pH LEVELS SANITATION COVERS SAFETY COVERS POOL COVER AUTOMATION SAFETY POOL SAFETY GUIDELINES SAFETY TIPS FOR PETS SAFETY EQUIPMENT ADA STANDARDS

INTRODUCTIONA swimming pool, swimming bath, wading pool, paddling pool, or simply a pool, is a container filled with water intended for swimming or water-based recreation.

HISTORYThe "Great Bath" at the site of Mohenjo-Daro in modern-day Pakistan was most likely the first swimming pool, dug during the 3rd millennium BC. This pool is 12 by 7 meters, is lined with bricks and was covered with a tar-based sealant.Ancient Greeks and Romans built artificial pools for athletic training in the palaestras, for nautical games and for military exercises. Roman emperors had private swimming pools in which fish were also kept, hence one of the Latin words for a pool, piscina. The first heated swimming pool was built by Gaius Maecenas of Rome in the first century BC. Gaius Maecenas was a rich Roman lord and considered one of the first patrons of arts.Ancient Sinhalese built pairs of pools called "Kuttam Pokuna" in the kingdom of Anuradhapura, Sri Lanka in the 4th century BC. They were decorated with flights of steps, punkalas or pots of abundance and scroll design.Swimming pools became popular in Britain in the mid 19th century. By 1837, six indoor pools with diving boards were built in London, England. The oldest surviving Swimming Club in Britain is believed to be Maidstone Swimming Club in Maidstone, Kent, England. It was formed in 1844 when there was concern over drownings in the River Medway. Rescuers would often die in the water because they could usually not swim to safety themselves. The club used to swim in the river and would hold races, diving competitions and water polo matches in the Medway. The South East Gazette July 1844 reported an aquatic breakfast party. Coffee and biscuits were served on a floating raft in the river, the coffee was kept hot over a fire and club members had to tread water and drink coffee at the same time. The last swimmers managed to overturn the raft to the amusement of the 150 spectators.After the modern Olympic Games began in 1896 and included swimming races, the popularity of swimming pools began to spread. In 1839, Oxford had its first major public indoor pool at Temple Cowley, and swimming began to take off. The Amateur Swimming Association was founded in 1869 in England, and the Oxford Swimming Club in 1909 with its home at Temple Cowley Pool. The presence of indoor baths in the cobbled area of Merton Street, London may have persuaded the less hardy of the aquatic brigade to join. So, bathers gradually became swimmers, and bathing pools swimming pools.

In the USA, the Racquet Club of Philadelphia clubhouse (1907) boasts one of the world's first modern above-ground swimming pools. The first swimming pool to go to sea on an ocean liner was installed on the White Star Line's Adriatic in 1907.Interest in competitive swimming grew following World War I. Standards improved and training became essential. Home swimming pools became popular in the United States after World War II and the publicity given to swimming sports by Hollywood films like Esther Williams Million Dollar Mermaid made a home pool a desirable status symbol. More than fifty years later, the home or residential swimming pool is ubiquitous and even small nations enjoy a thriving swimming pool industry (e.g. New Zealand pop. 4,116,900 [Source NZ Census 7 March 2006] - holds the record in pools per capita with 65,000 home swimming pools and 125,000 spa pools). A two-storey, white concrete swimming pool building composed of horizontal cubic volumes built in 1959 at the Royal Roads Military College is on the Registry of Historic Places of Canada.

DIMENSIONSLength: Most pools in the world are measured in metres, but in the United States pools are often measured in feet and yards. In the United Kingdom most pools are in meters, but older pools measured in yards still exist. In the US, pools tend to either be 25 yards (SCY-short course yards), 25 metres (SCM-short course metres) or 50 metres (long course). US high schools and the NCAA conduct short course (25 yards) competition. There also exist many pools 33 m long, so that 3 lengths = 100 m. This pool dimension is commonly used to accommodate water polo.USA Swimming (USA-S) swims in both metric and non-metric pools. However, the international standard is metres, and world records are only recognized when swum in 50 m pools (or 25 m for short course). In general, the shorter the pool, the faster the time for the same distance, since the swimmer gains speed from pushing off the wall after each turn at the end of the pool.Width: Most European pools are between 10 m and 50 m wide.Depth: The depth of a swimming pool depends on the purpose of the pool, and whether it is open to the public or strictly for private use. If it is a private casual, relaxing pool, it may go from 1.0 to 2.0 m (3.3 to 6.6 ft) deep. If it is a public pool designed for diving, it may slope from 3.0 to 5.5 m (9.8 to 18.0 ft) in the deep end. A children's play pool may be from 0.3 to 1.2 m (1 to 4 ft) deep. Most public pools have differing depths to accommodate different swimmer requirements. In many jurisdictions, it is a requirement to show the water depth with clearly marked depths affixed to the pool walls.SHAPESInfinity PoolsInfinity pools (also called vanishing-edge or negative-edge pools) are one of the most dramatic effects found in pool design. Made to fool the viewer into believing that the pool flows over an edge into the neighboring vista, this type of swimming pool is actually a product of math and science: the water flows over the pools weir wall into a hidden trough where its recycled back into the pool. Homes that overlook spectacular scenery like the ocean, a river, mountains, or even nearby cityscapes are the best candidates to capture this designs magic. However, a designer will also suggest an infinity pool for a property that is surrounded by natural lushness like wooded glens or palm tree groves.

Perimeter-Overflow PoolsThis deck-level perimeter-overflow pool includes one side that works like an infinity edge, taking full advantage of the propertys oceanfront view.Perimeter overflow pools are an optical illusion that uses water to mimic mirrors and flat deck surfaces. Water overflows on all sides into a trough in the deck, functioning like a 360-degree vanishing edge. When viewed from overhead or from afar, the pool appears to be a flat surface on the deck. It is only when the wind or some other movement ripples the surface that the effect disappears.Concrete, vinyl, and fiberglass pools can all incorporate infinity edges and perimeter overflows into their designs.

Classic Rectangle and Lap PoolsIf your home is luxurious and traditional, then a classic rectangle is one of the best options as the pools straight lines will not overpower the propertys ageless elegance; in fact, those clean edges will reinforce the architectures magnificence, creating an even greater aura of sophistication.But dont let your imagination stop there. Rectangular pools are the little black dress of pool design. In fact, many designers prefer to use this shape for non-traditional homes because it never goes out of style and will always coordinate perfectly with its surroundings. Rectangular pools can fit into a variety of locations, including contemporary, urban, and pastoral. When joined with an infinity edge or a perimeter overflow, this type of inground pool shape takes on even more character and allows the pool to truly become one with the setting.

In addition to gracefully enhancing a homes property, a rectangular pool can also be put to work. Many people enjoy using the pool for exercise and swimming laps. A lap pool is an excellent option for those who want more out of their pool than a place to dip their toes or float away the day. Built to accommodate a swimmers strokes and turns, a lap pool can be whatever length and width the user deems necessary. But dont think that your pool must be utilitarian in looksuse your professional pool designers flair for the visual and keep the aesthetic around the pool in line with the rest of the property so the pool can also be the homes showpiece. By simply changing the design to create an L shape, the pool can be the best of both worlds: for those swimming laps, there is the straightaway, and for those wishing to play water volleyball or basketball, there is a separate wading area for fun and games.

Freeform PoolsFreeform pools live up to their name: Because their contours do not have to obey the rules of geometry, they can become whatever the designer visualizes, making them ideal for most properties. Homes in natural, tropical, or rustic settings are exceptional candidates because freeform pools blend in seamlessly with their surroundings, morphing into the setting and appearing to be organic in origin. With imaginative landscaping, hardscaping, and lighting, a freeform pool can mimic a tropical lagoon, a secret oasis, or a tranquil waterway.Freeform pools are also excellent choices for homeowners who want to incorporate a pool into an asymmetrical space that is already developed. The designer will finish the pool to match the surroundings, thus keeping the poolscape in sync with the entire outdoor space.

Geometric PoolsGeometric pools rely on mathematics for their sharp good looks, and like the geometric gems created by the cubist masters, they instantly become enduring works of art. Coupled with special design features like fountain bubblers, vanishing edges, overflows, and spillways, this type of swimming pool is the choice for those seeking the ultimate in haute couture.Full of squares, rectangles, triangles, and other carefully formulated shapes, geometric pools are best suited for contemporary or modern properties. They become an extension of the homes ascetic appeal, providing the perfect counterpart to the propertys overall beautywhich is the reason why geometric pools also work well in desert or other Spartan environments.Custom PoolsSome homes require a unique look that goes beyond the common pool shapes: they need something that is completely their own. Most often, a homeowner gives the pool designer carte blanche to create a one-of-a-kind poolscape that incorporates every nuance and element found on their property.Usually, these types of pools are built from concrete because this versatile material can accommodate every size and shape that can be imagined. For instance, if your home overlooks magnificent panorama like an ocean or a graceful mountain range, you may want your builder to combine the magical effects of an infinity pool with a freeform lagoon style. Over the years, homeowners and designers have let their imaginations fly: guitar-shaped, fish-shaped, even car-shaped pools have been the result. Designers have built cantilevered pools off the sides of mountains, creating breathtaking infinity pools that belie gravity. They have also created meandering pools that mimic lazy rivers and invisible-sided pools that appear to be floating on airthe options are limitless. Custom pools are for the homeowner who is fearless and ready to create a poolscape that has never been seen before.

Kidney shaped PoolsIf you peeked over the fence of every home that has a swimming pool, you will notice that quite a few sport a kidney-shaped pool. The reason is simple: kidney-shaped pools soft, retro look is appropriate for a variety of architectural styles.Many pool designers use this pool shape as a foundation from which to build more elaborate structures. No matter the building material, they will add accents like natural coping, glass tile, colorful plaster, or a textured finish to customize the project for your property.

Grecian and roman poolsGrecian and Roman style pools are classic rectangles gone wild. Mirroring the formal elements found in ancient art, these pools start out as rectangles and then get pushed and pulled into something completely different.Grecian pools have cut corners, forming an octagon, while Roman pools have stylized corners and rounded ends. Both types blend in with a variety of homes, but especially those of Tuscan or Aegean heritage. When finished in a colorful glass tile and framed with Travertine coping or decking, one can easily mistake either one as a relic from another era.

In the end, the swimming pool needs to be shaped for you and your property. When your project is done, there should be complete harmony throughout the space. The home, the inground pool, the outdoor structures and the landscaping that frames your backyard should all be in sync with each other. Then, when you look around your new favorite spot, you can applaud your designer and builderand yourselffor a job well done.

TYPESPools can be either indoors or outdoors. They can be of any size and shape, and inground or above ground. Most pools are permanent fixtures, while others are temporary, collapsible structures.

Private poolsPrivate pools are usually smaller than public pools, on average 3.7 m 7.3 m (12 ft 24 ft) to 6.1 m 12.2 m (20 ft 40 ft) whereas public pools usually start at 24 m (80 ft).[citation needed] Home pools can be permanently built-in, or be assembled above ground and disassembled after summer. Privately owned outdoor pools in backyards or gardens started to proliferate in the 1950s in regions with warm summer climates, particularly in the United States.Private pools are increasingly a feature of homes in greater latitudes. For example, in London many larger homes are now refurbished with indoor pools, usually in the basement or in a conservatory.Construction methods for private pools vary greatly. The main types of in-ground pools are gunite Shotcrete, concrete, vinyl-lined, and one-piece fiberglass shells.Many countries now have strict pool fencing requirements for private swimming pools, which require pool areas to be isolated so that unauthorized children younger than six years cannot enter. Many countries require a similar level of protection for the children residing in or visiting the house, although many pool owners prefer the visual aspect of the pool in close proximity to their living areas, and will not provide this level of protection. There is no consensus between states or countries on the requirements to fence private swimming pools, and in many places they are not required at all, particularly in rural settings.

Children's poolsInexpensive temporary Polyvinyl chloride pools can be bought in supermarkets and taken down after summer. They are used mostly outdoors in yards, are typically shallow, and often their sides are inflated with air to stay rigid. When finished, the water and air can be let out and this type of pool can be folded up for convenient storage. They are regarded in the swimming pool industry as "splasher" pools intended for cooling off and amusing toddlers and children, not for swimming, hence the alternate name of "kiddie" pools.Toys are available for children and other people to play with in pool water. They are often blown up with air so they are soft but still reasonably rugged, and can float in water.

Public poolsPublic pools are often part of a larger leisure centre or recreational complex. These centres often have more than one pool, such as an indoor heated pool, an outdoor (chlorinated, saltwater or ozonated) pool which may be heated or unheated, a shallower children's pool, and a paddling pool for toddlers and infants. There may also be a sauna and one or more hot tubs or spa pools ("jacuzzis").Many upscale hotels and holiday resorts have a swimming pool for use by their guests. If a pool is in a separate building, the building may be called a natatorium. The building may sometimes also have facilities for related activities, such as a diving tank. Larger pools sometimes have a diving board affixed at one edge above the water.Many public swimming pools are rectangles 25 m or 50 m long, but they can be any size and shape. There are also elaborate pools with artificial waterfalls, fountains, splash pads, wave machines, varying depths of water, bridges, and island bars.Some swimming facilities have lockers for clothing and other belongings. The lockers can require a coin to be inserted in a slot, either as deposit or payment. There are usually showers - sometimes mandatory - before and/or after swimming. There are often also lifeguards to ensure the safety of users.Wading or paddling pools are shallow bodies of water intended for use by small children, usually in parks. Concrete wading pools come in many shapes, traditionally rectangle, square or circle. Some are filled and drained daily due to lack of a filter system. Staff chlorinate the water to ensure health and safety standards.

Competition poolsA simplified diagram of the FINA long course swimming pool standard, used at the World Championships and Summer OlympicsThe Fdration Internationale de la Natation (FINA, International Swimming Federation) sets standards for competition pools: 25 or 50 m (82 or 164 ft) long and at least 1.35 m (4.4 ft) deep. Competition pools are generally indoors and heated to enable their use all year round, and to more easily comply with the regulations regarding temperature, lighting, and automatic officiating equipment.An Olympic-size swimming pool (first used at the 1924 Olympics) is a pool that meets FINA's additional standards for the Olympic Games and for world championship events. It must be 50 m (160 ft) in length by 25 m (82 ft) wide, divided into eight lanes of 2.5 m (8.2 ft) each plus two areas of 2.5 m (8.2 ft) at each side of the pool. The water must be kept at 2528 C (7782 F) and the lighting level at greater than 1500 lux. Depth must be at least 2 m (6.6 ft), and there are also regulations for color of lane rope, positioning of backstroke flags (5 meters from each wall), and so on. Pools claimed to be "Olympic pools" do not always meet these regulations, as FINA cannot police use of the term. Touchpads are mounted on both walls for long course meets and each end for short course.A pool may be referred to as fast or slow, depending on its physical layout. Some design considerations allow the reduction of swimming resistance making the pool faster: namely, proper pool depth, elimination of currents, increased lane width, energy absorbing racing lane lines and gutters, and the use of other innovative hydraulic, acoustic and illumination designs.

Exercise poolsIn the last two decades, a new style of pool has gained popularity. These consist of a small vessel (usually about 2.5 m x 5 m) in which the swimmer swims in place, either against the push of an artificially generated water current or against the pull of restraining devices. These pools have several names, such as swim spas, swimming machines, or swim systems. They are all examples of different modes of resistance swimming.

Hot tubs and spa poolsHot tubs and spa pools are common heated pools used for relaxation and sometimes for therapy. Commercial spas are common in the swimming pool area or sauna area of a health club or fitness centre, in men's clubs, women's clubs, motels and exclusive five star hotel suites. Spa clubs may have very large pools, some segmented into increasing temperatures. In Japan, men's clubs with many spas of different size and temperature are common. Commercial spas are generally made of concrete, with a mosaic tiled interior. More recently with the innovation of the Pre-Form Composite method where Mosaic tiles are bonded to the shell this enables Commercial spas to be completely factory manufactured to specification and delivered in one piece. Hot tubs are typically made somewhat like a wine barrel with straight sides, from wood such as Californian redwood held in place by metal hoops. Immersion of the head is not recommended in spas or hot tubs due to a potential risk of underwater entrapment from the pump suction forces. However, commercial installations in many countries must comply with various safety standards which reduce this risk considerably.Home spas are a worldwide retail item in western countries since the 1980s, and are sold in dedicated spa stores, pool shops, department stores, the Internet, and catalog sales books. They are almost always made from heat-extruded acrylic sheet Perspex, often colored in marble look-alike patterns. They rarely exceed 6 m2 (65 sq ft) and are typically 1 m (3 ft 3 in) deep, restricted by the availability of the raw sheet sizes (typically manufactured in Japan). There is often a mid-depth seating or lounging system, and contoured lounger style reclining seats are common. Upmarket spas include various jet nozzles (massage, pulsating, etc.), a drinks tray, lights, LCD flat-screen TV sets and other features that make the pool a recreation center. Due to their family-oriented nature, home spas are normally operated from 36 to 39 C (97 to 102 F). Many pools are incorporated in a redwood or simulated wood surround, and are termed "portable" as they may be placed on a patio rather than sunken into a permanent location. Some portable spas are shallow and narrow enough to fit sideways through a standard door and be used inside a room. Low power electric immersion heaters are common with home spas.Whirlpool tubs first became popular in America during the 1960s and 1970s. A spa is also called a "jacuzzi" in USA since the word became a generic after plumbing component manufacturer Jacuzzi introduced the "Spa Whirlpool" in 1968. Air bubbles may be introduced into the nozzles via an air-bleed venturi pump that combines cooler air with the incoming heated water to cool the pool if the temperature rises uncomfortably high. Some spas have a constant stream of bubbles fed via the seating area of the pool, or a footwell area. This is more common as a temperature control device where the heated water comes from a natural (uncontrolled heat) geothermal source, rather than artificially heated. Water temperature is usually very warm to hot 38 to 42 C (100 to 108 F), so bathers usually stay in for only 20 to 30 minutes. Bromine or mineral sanitizers are often recommended as sanitizers for spas because chlorine dissipates at a high temperature thereby heightening its strong chemical smell. Ozone is an effective bactericide and is commonly included in the circulation system with cartridge filtration, but not with sand media filtration due to clogging problems with turbid body fats.

Ocean poolsIn the early 20th century, especially in Australia, ocean pools were built, typically on headlands by enclosing part of the rock shelf, with water circulated through the pools by flooding from tidal tanks or by regular flooding over the side of the pools at high tide. This continued a pre-European tradition of bathing in rockpools, or bogey holes with many of the current sites being expanded from sites used by Australian Aborigines. Bathing in these pools provided security against both rough surf and sharks. There were often separate pools for women and men, or the pool was open to the sexes at different times with a break for bathers to come without fear of observation by the other sex.These were the fore-runners of modern 'Olympic' pools. A variation was the later development of sea- or harbour-side pools that circulated sea water using pumps. A pool of this type was the training ground for Australian Olympian Dawn Fraser.There are currently about 100 ocean baths in New South Wales, which can range from small pools roughly 25 metres long and "Olympic Sized" (50m) to the very large, such as the 50x100m baths in Newcastle. While most are free, a number charge fees, such as the Bondi Icebergs pool at Bondi Beach. Despite the development of chlorinated and heated pools, ocean baths remain a popular form of recreation in New South Wales.

Infinity poolsAn infinity edge pool (also named negative edge or vanishing edge pool) is a swimming pool which produces a visual effect of water extending to the horizon, vanishing, or extending to "infinity". Often, the water appears to fall into an ocean, lake, bay, or other similar body of water. The illusion is most effective whenever there is a significant change in elevation, though having a natural body of water on the horizon is not a limiting factor.

Natural pools and pondsNatural pools were developed in central and western Europe in the early and mid-1980s by designers and landscape architects with environmental concerns. They have recently been growing in popularity as an alternative to traditional swimming pools. NSPs are constructed bodies of water in which no chemicals or devices that disinfect or sterilize water are used, and all the cleaning of the pool is achieved purely with the motion of the water through biological filters and plants rooted hydroponically in the system. In essence, NSPs seek to recreate swimming holes and swimmable lakes, the environment where people feel safe swimming in a non-polluted, healthy, and ecologically balanced body of water.Water in NSPs has many desirable characteristics. For example, red eyes, dried-out skin and hair, and bleached bathing suits associated with overly chlorinated water are naturally absent in NSPs.[citation needed] NSPs, by requiring a water garden to be a part of the system, offer different aesthetic options and can support amphibious wild life such as snails, frogs, and salamanders.

Zero-entry swimming poolsA zero-entry swimming pool, also called a beach entry swimming pool, is a swimming pool having an edge or entry that gradually slopes from the deck into the water, becoming deeper with each step, in the manner of a natural beach. As there are no stairs or ladders to navigate, this type of entry assists older people, young children and people with accessibility problems where gradual entry is useful.

How does a pool workConceptually, swimming pools are pretty simple -- they're just big basins of water. But on a hot summer day, a swimming pool can seem like the greatest invention known to man. And as it turns out, there really is a lot of cool technology at work in your average pool -- much more than you might expect.In this article, we'll find out how pools are built, and we'll take a look at the plumbing system that keeps the water clean and chemically balanced.Pool BasicsSwimming pools come in all shapes and sizes, but nearly all of them, from the backyard personal pool to the water park wave pool, work in the same basic way. They use a combination of filtration and chemical treatment to continually clean a large volume of water. A typical swimming pool needs seven major components: A basin A motorized pump A water filter A chemical feeder Drains Returns PVC plastic plumbing connecting all of these elementsThe basic idea is to pump water in a continual cycle, from the pool through the filtering and chemical treatment systems and back to the pool again. In this way, the pumping system keeps the water in the pool relatively free of dirt, debris and bacteria. Some pools also include heaters in the mix, in order to keep the water at a certain temperature.

CONSTRUCTION Above-ground poolsare the cheapest construction option, as well as the easiest to build. Most above-ground pools are made from prefabricated kits, which even an amateur can put together (though most people go with professional installers). First, the installers level off the ground to form a flat building surface. Then they assemble a perimeter track, which supports the outer wall (made of metal, plastic or wood). Next, they spread sand in the pool area and lay theplumbing. Finally, they secure the vinyl liner over the pool walls, fill the pool with water, smooth the liner and fasten it into place. As soon as they hook up the pump and filtering system, the pool is ready to go. The main disadvantage of this sort of pool is that it's less durable than other designs, and generally less attractive. It's also less permanent, which can be a good thing -- it's relatively easy to disassemble the pool and move it to a new location.

Fiberglass poolsare made from fiberglass-reinforced plastic, which has been molded into a basin shape. To install the pool, a construction crew digs an appropriately sized hole, lays the necessary plumbing, adds some sand filler and lowers the preformed pool structure into the hole. Then they level the pool, hook up all the plumbing and backfill in the area around the pool. Usually, the pool is surrounded by a concrete deck structure.

Vinyl-lined in-ground poolsare a lot like above-ground pools, structurally, but they look more like conventional in-ground designs. The construction crew digs a hole and assembles a metal, plastic or wood frame wall around the hole's perimeter. As in an above-ground pool, the crew lays sand along the bottom of the hole and secures the vinyl lining to the structural wall. These pools are a lot cheaper than other in-ground designs, but not as durable. Typically, the liner needs to be replaced every 10 years or so.

Gunite poolsare the most popular design in much of the United States. To build one of these pools, the construction crew digs a hole, puts the plumbing in place and assembles a framework grid with 3/8-inchsteelreinforcing rods (rebar). The rebar rods are spaced about 10 inches apart, and secured together with wire. When the grid is in place, the crew sprays a heavy coating ofgunite, a mixture of cement and sand, around the rebar. The sprayer unit combines dry gunite mix with water just before spraying -- this produces the wet concrete material. The crew trowels the gunite smooth and lets it sit for a week or so before applying a smooth finish to the rough surface. The most popular finish is calledplaster(actually a mixture of cement and marble sand), but a lot of people finish their pools with special concrete paint. Gunite pools can also have tile, exposed aggregate or even fiberglass finishes. Gunite pools (and their cousins,shotcretepools) are highly durable, and they can be built in any shape or size.

Poured-concrete poolsare similar to gunite pools, but they're a lot harder to build. Instead of spraying concrete material around a rebar framework, concrete is actually poured into conventional wooden forms. With the rise of gunite methods, poured-concrete pool construction has mostly fallen by the wayside. In masonry block pools, the walls are constructed with concrete blocks.While these pool designs are quite different, they all rely on the same basic plumbing and filtering systems. In the next few sections, we'll see how these components actually keep the pool going.

Pool Drain SystemsWe've already seen that the water in a swimming pool needs to circulate through a filtering system, to remove dirt and debris. During normal operation, water flows to the filtering system through two or more main drains at the bottom of the pool and multiple skimmer drains around the top of the pool.The main drains are usually located on the lowest point in the pool, so the entire pool surface slants toward them. Most of the dirt and debris that sinks exits the pool through these drains. To keep people from getting their hair or limbs caught in the plumbing, the drains are almost always covered with grates or antivortex covers (a cover that diverts the flow of water to prevent a dangerous vortex from forming). The skimmers draw water the same way as the main drains, but they suck only from the very top of the pool (the top eighth of an inch, typically). Any debris that floats -- leaves, suntan oil, hair -- leaves the pool through these drains. The diagram below shows a common system.In the system described here, the floating weir, the door at the inlet passageway, swings in and out to let a very small volume of water in at a time. To catch debris effectively, the goal is to skim just the surface level. The water flows through the strainer basket, which catches any larger debris, such as twigs and leaves. In addition to the main inlet, the skimmer system has a secondary equalizer line leading to a drain below the surface level. This line keeps the skimmer from drawing air into the pump system if the water level drops below the level of the main inlet.The water is pumped through the filtering system and back out to returns, inlet valves around the side of the pool. This system involves a lot of suction, but if the pool is built and operated correctly, there is virtually no risk of suction holding somebody against one of the drains. The only way the plumbing system could apply this sort of suction is if there were only one open drain. In a safe pool, there are always multiple main drains as well as several skimmer drains, so if somebody or something blocks one drain, the pumping system will pull water from one of the other drains. This eliminates the suction on the blocked drain.Most swimming pools also have a couple of vacuum ports, which are only used in pool cleaning. These ports attach to pool vacuum cleaners, which work something like ordinary vacuum cleaners except that they suck water instead of air. The vacuum ports may have their own pumping system, but in most pools they are driven by the main pump.After making its way into the various drains, the water flows on to the filtering stage. In the next section, we'll find out what the pumping and filtering systems are all about.

Pool Pump SystemsTo most of us, a pool is, more or less, a big hole in the ground. We don't see most of the expensive machinery in a pool system, because it's usually tucked away in nearby pump room. But this is the stuff that really makes the pool work.The heart of the pool system is the water pump. In a typical pump system, an electric motor spins an impeller inside the pump housing. The impeller drives the water from the various drains through the filter and back out to the water inlets.Just before it flows into the pump, the water passes through a metal strainer basket that catches leaves and other large debris that might clog up the pump. Next, the water flows into the filter (or, in this setup, one of two filters). In the next section, you'll find out what happens at this point in the system.

Pool FiltersThe filters in this system are high-rate sand filters. Sand filters consist of a large tank, made of fiberglass, concrete or metal, containing a thick bed of special-grade sand, which has a squarish shape.During filtering operation, dirty water from the pool comes in through the filter's inlet pipe, which leads to the water distribution head inside the tank. While gravity pulls the water down through the sand, the tiny sand particles catch any dirt and debris. At the bottom of the tank, the filtered water flows through the pick-up unit and out the outlet pipe.Over time, the collected dirt and debris in the sand slows down the water flow. Pressure gauges at the filter inlet and outlet give the pool custodian an idea of the blockage level inside. If gauges show much greater pressure on the inlet pipe than the outlet pipe, the custodian knows there's a lot of collected debris in the sand. This means it's time to backwash the filter. To backwash, the custodian adjusts a number of valves to redirect the water flow. He or she closes the return pipe leading to the pool and opens the drainage pipe, which lead to the sewer system. He or she adjusts a valve at the filter to connect the pipe from the pump to the outlet pipe and connect the drainage pipe to the inlet pipe. With this arrangement, water from the pump pushes up through the sand, dislodging the dirt and debris. At the top of the filter tank, the dirty water flows out through the inlet pipe and into the sewer. To redirect the water flow for backwash, the custodian turns large handles to adjust plumbing valves.In place of a sand filter, some pool systems use a diatomaceous earth filter or a cartridge filter. In a diatomaceous earth filter, water from the pool passes through filter grids coated with diatomaceous earth, a fine powder made from the chemically inert, fossilized remains of sea organisms called diatoms. In a cartridge filter, dirty water passes through a filter made out of polyester cloth or corrugated paper. Instead of backwashing, you simply remove the filter and hose it off. After a few years (or as many as eight years), it's time to discard the old filter and put in a new one.In most regions, the law dictates that all the water in the pool (or more accurately, the equivalent volume) must pass through the filter in a certain amount of time -- typically between 30 minutes and six hours. For the apartment-complex pool pictured above, that means pumping 167,000 gallons (630,000 liters) of water through the filtering system every six hours!The pump and filter system is also connected to a well or municipal water line so fresh water can be added to the pool. This is necessary to replace water lost to evaporation, backwashing and "splash-out" (water that splashes on the deck or is carried out on people's bodies and swim suits). When it's pretty hot out and there's heavy swimmer activity, this 167,000-gallon pool could lose 300 gallons (1,100 liters) or more in one day.

Pool ChemicalsA pool's filter system does the heavy lifting in keeping the water clean, but it takes chemistry to do the fine-tuning. It's important to carefully manipulate the chemical balance in pools for several reasons:Dangerous pathogens, such as bacteria, thrive in water. A pool filled with untreated water would be a perfect place for disease-carrying microorganisms to move from one person to another.Water with the wrong chemical balance can damage the various parts of the pool.Improperly balanced water can irritate the skin and eyes.Improperly balanced water can get very cloudy.To take care of pathogens in the water, you have to introduce a disinfecting agent that will get rid of them. The most popular pool disinfectant is the element chlorine, in the form of a chemical compound such as calcium hypochlorite (a solid) or sodium hypochlorite (a liquid). When the compound is added to the water, the chlorine reacts with the water to form various chemicals, most notably hypochlorous acid. Hypochlorous acid kills bacteria and other pathogens by attacking the lipids in the cell walls and destroying the enzymes and structures inside the cell through an oxidation reaction. Alternative sanitizers, such as bromide, do basically the same thing with slightly different results.Chlorine is typically prepared in liquid, powder or tablet form (though some professionals use gaseous chlorine), and it can be added to the water anywhere in the cycle. Pool experts generally recommend adding it just after the filtering process, using a chemical feeder. If it's added directly into the pool, using tablets in the skimmer boxes, for example, the chlorine tends to be too concentrated in those areas.One problem with hypochlorous acid is that it's not particularly stable. It can degrade when exposed to ultraviolet light from the sun, and it may combine with other chemicals to form new compounds. Pool chlorinators often include a stabilizing agent, such as cyanuric acid, that reacts with the chlorine to form a more stable compound that does not degrade as easily when exposed to ultraviolet light.Even with a stabilizing agent, hypochlorous acid may combine with other chemicals, forming compounds that are not very effective sanitizers. For example, hypochlorous acid may combine with ammonia, found in urine, among other things, to produce various chloramines. Not only are chloramines poor sanitizers, but they can actually irritate the skin and eyes and have an unpleasant odor. The distinctive smell and eye irritation associated with swimming pools are actually due to chloramines, not ordinary hypochlorous acid -- a strong smell usually means there is too little free chlorine (hypochlorous acid), rather than too much. To get rid of chloramines, pool custodians have to shock treat the pool -- add an unusually strong dose of chemicals to clear out organic matter and unhelpful chemical compounds.Chloramine formation is related to the second major element in pool chemistry, maintaining the right pH in the pool.

Pool pH LevelsThe water's pH is a measure of its total acid-alkalinity balance -- the relative proportion of acids and alkalis in the water (check out Chem4Kids: Acids & Bases for a description of acids and alkalis). Simply put, water that is either too acidic or too alkaline will cause undesirable chemical reactions. If the water is too acidic, it will corrode metal equipment, cause etching on the surface materials and cause skin irritation. If the water is too alkaline, it can cause scaling on the pool surface and plumbing equipment and can cloud the water. Additionally, both high acidity and high alkalinity alters the effectiveness of the chlorine. The chlorine won't destroy pathogens as well if the water is too alkaline, and it will dissipate much more quickly if the water is too acidic.On the pH scale, zero indicates extreme acidity, 14 indicates extreme alkalinity and 7 indicates a neutral state. Most pool experts recommend a pool pH between 7.2 and 7.8. To raise or lower pH, a pool custodian simply adds acids or alkalis into the water. For example, adding sodium carbonate (soda ash) or sodium bicarbonate (baking soda) will generally raise the pH, and adding muriatic acid or sodium bisulfate will lower the pH.Maintaining the proper balance of chemicals in the pool is a continual process, because any new element -- oils from a swimmer's body, a shot of chlorine, stuff that falls in the water -- shifts the water's total chemical makeup. In addition to pH, pool custodians also monitor total alkalinity, calcium hardness and total dissolved solids.When you consider all the chemistry and machinery involved in swimming pools, it's clear that they really are remarkable pieces of technology. It takes a surprising amount of work and ingenuity to build and maintain these summertime staples.

SanitationSwimming pool water must maintain low levels of bacteria and viruses to prevent the spread of diseases and pathogens. Bacteria, algae and insect larvae can enter the pool if water is not properly sanitized. Pumps, mechanical filters, and disinfectants are often used to sanitize the water.Chemical disinfectants, such as chlorine (usually as a hypochlorite salt, such as calcium hypochlorite) and bromine, are commonly used to kill pathogens. If not properly maintained, chemical sanitation can produce high levels of Disinfection byproducts. Sanitized swimming pool water can theoretically appear green if iron or certain minerals (such as copper chloride) are in the water.CoversSwimming pool heating costs can be significantly reduced by using a pool cover. Use of a pool cover also can help reduce the amount of chemicals (chlorine, etc.) required by the pool. Outdoor pools gain heat from the sun, absorbing 75%85% of the solar energy striking the pool surface. Though a cover decreases the total amount of solar heat absorbed by the pool, the cover eliminates heat loss due to evaporation and reduces heat loss at night through its insulating properties. Most swimming pool heat loss is through evaporation.The heating effectiveness of a cover depends on type. A transparent bubble cover is the most effective, as it allows the largest amount of solar flux into the pool itself. Thermal bubble covers are lightweight UV stabilized floating covers designed to minimize heat loss on heated swimming pools. Typically they are only fitted in spring and fall (autumn) when the temperature difference between pool water and air temperature is greatest. They raise temperature of a pool by around 20 Fahrenheit, or 11 Celsius, after being on the pool for a week. Bubble covers are typically applied and removed by being rolled up on a device fitted to one side of the pool (see illustration). Covers fall apart after 4 or 5 years due to sun exposure, overheating in the sun while off the pool, and chlorine attacking the plastic. Bubble covers should be removed during super chlorination.A vinyl cover absorbs more sunlight directly, allowing temperature to rise faster, but ultimately prevents the pool from reaching as high a temperature as a clear cover. Vinyl covers consist of a heavier material and have a longer life expectancy than bubble covers. Insulated vinyl covers are also available with a thin layer of flexible insulation sandwiched between two layers of vinyl.These covers are mandatory[citation needed] to be fitted to all pools in areas of Australia that have experienced drought since 2006. This is an effort to conserve water, as much water evaporates and transpires.An alternative to a continuous sheet of pool covering is multiple floating disks which are deployed and removed disk by disk. They cover most of the surface of the pool and offer evaporation reduction similar to continuous covers. Various types are available, for example opaque (for UV resistance and possible reduced algal growth), transparent (for esthetics), heavy and solid (for wind resistance), light and inflatable (for ease of handling).

Safety coversThese covers are typically attached all winter, by hooked bungee cords or hooked springs connected to the pool deck, and are usually made in a variety of materials including coated or laminated vinyl or polypropylene mesh. They are custom designed to stop leaf debris from entering the pool but more importantly they also provide safety for animals and small children when designed and installed properly. The custom safety cover was invented in 1957 by Fred Meyer Jr. of Meyco Pool Covers when he found a dead animal in his pool. Today covers are made to meet ASTM safety barrier standards and have kept animals, people and even large vehicles out of the pool. They are not popular in warmer climates, due to the five to ten minutes it takes to fit/remove them, making them inconvenient for repeated application and removal.

Pool cover automationA pool cover can be either manually, semi-automatically, or automatically operated. Manual covers can be folded and stored in an off site location. Pool cover reels can also be used to help manually roll up the pool cover. The reel, usually on wheels, can be rolled in or out of place.Semi-automatic covers use a motor-driven reel system. They use electrical power to roll and unroll the cover, but usually require someone to pull on the cover when unrolling, or guide the cover onto the reel when rolling up the cover. Semi-automatic covers can be built into the pool deck surrounding the pool, or can use reels on carts.Automatic covers have permanently mounted reels that automatically cover and uncover the pool at the push of a button. They are the most expensive option, but are also the most convenient. These reels can be run from either an external motor requiring a pit to be dug beside the pool or using an internal motor that spins the reel.Some pool covers fit into tracks along the sides of the pool. This prevents anything or anybody from getting into the pool. They even support the weight of several people. They can be run manually, semi-automatically, or automatically. Safety covers may be required by inspectors for public pools.

SafetyPools present a significant risk of infant and toddler death due to drowning. In regions where residential pools are common, drowning is a major cause of childhood fatalities. As a precaution, many municipalities have by-laws that require that residential pools be enclosed with fencing to restrict unauthorized access. The Virginia Graeme Baker Pool And Spa Safety Act regulates pools to reduce the risk of entrapment. Diving in the shallow end can also lead to significant head and neck injuries; diving, especially head-first diving, should be done in the deepest point of the pool, minimally 2.4 m (7 ft 10 in), but desirably 3.7 m (12 ft), deeper if the distance between the water and the board is great.Many products exist, such as removable baby fences, floating alarms and window/door alarms. Some pools are equipped with computer-aided drowning prevention or other forms of electronic safety and security systems.Suspended ceilings in indoor swimming pools are safety-relevant components. The selection of materials under tension should be done with care. Especially the selection of unsuitable stainless steels can cause problems with stress corrosion cracking.

Pool Safety GuidelinesChild SafetyThe National Safety Council reports that 600 children and adults drown annually in swimming pools, 330 in home pools. By communicating these pool tips effectively as well as using common sense, your backyard pool can be a safe and pleasurable experience for children as well as adults. Check local ordinances and codes for safety requirements. Use non-slip materials on the pool deck, diving board and ladders. The steps of the pool ladder should be at least three inches wide, and the ladder should have handrails on both sides small enough for a child to grasp. There should be a ladder at both ends of the pool. Electrical equipment should be installed by a licensed electrician in accordance with local safety codes. Check with a professional pool contractor to be sure the depth is sufficient for a diving board or slide. Always put a slide in a deep area of the pool-- never in shallow water. There should be a fence at least six feet high around all sides of the pool with a locked gate to keep children out when there is no supervision and the fence should be constructed so it is difficult to climb. Lawn furniture, trees and shrubs should not be close enough to provide an easy boost over the fence. Avoid using a side of the house as part of the fence; toddlers have wandered out through an open patio door or window and drowned. Mark water depths conspicuously. Use a safety float line where the bottom slope deepens. Above-ground pools: Install sturdy guard rails around the pool deck. Look for rolled rims on the metal shell to be sure the rims do not present a sharp cutting edge if someone falls. The access ladder to the deck should be sturdy and without protruding bolts or other sharp edges. The access ladder should swing up to prevent children from unauthorized entry or should be easily removable for secure storage away from the pool area. Check the pool and equipment periodically for cleanliness and good maintenance. Cover all sharp edges and protruding bolts; repair rickety or broken ladders and railings. Replace non-slip materials when they wear out. Teach children to float or swim as soon as possible. Always provide competent adult supervision when the pool is in use. No one should ever swim alone. Caution children against showing off and playing rough and explain the dangers of running and diving recklessly. Never push others into the pool. When using water slides, always go feet first. Before diving or sliding, check to be sure that other swimmers are out of the way. Keep rescue devices and first aid supplies near the pool. Teach children what to do in case of emergency. An alarm bell that could summon help would be a good idea. Keep electrical appliances such as radios out of the pool area because of the hazard of electrical shock. Never swim after drinking alcoholic beverages, eating or taking medications.

Safety Tips for PetsThere are some basics rules you can follow to prevent tragedy when pets are around the family pool. First, your pet should always be taught where the steps in the pool are located, in case he falls in or gets in trouble while swimming. Even pets that are experienced swimmers can sometimes panic if they accidentally fall in the swimming pool. Pets that are too small to use steps should not be allowed in the pool.Here are some other helpful strategies for keeping your pet safe: A fence should be installed around the pool. Install a pet-safe ladder in the pool so your pet has easy exit access. Pets should not be allowed around the pool without supervision. Pool covers are NOT a form of protection. Covers can be deceptive to pets, as they look like a solid surface but can give out and lead to a tragedy. Familiarize your pet with water at a young age; dont assume he can swim. Consider purchasing a pool alarm system. These float in the pool and go off when there is a disturbance in the water. Take your pet to the veterinarian immediately if a near-drowning or water injury occurs.

Safety EquipmentThere are many products that can be added to your backyard pool area when considering pool safety. Whether you are protecting your young children, older adults or even your pets, keeping your backyard up to date with the latest safety features is of the utmost importance. Here are a few products that you may want to consider:

Pool FencesPool fences are one of the more common ways to ensure safety and are usually gate-locked and childproof. Many pool fences are designed for ease of use and restrict the occurrence of broken or sticking hinges and mechanisms. Alternatively, a temporary and removable pool fence can also be used to be set up only whenever children visit the household; though, a more permanent fence is recommended.

Four-sided Isolation FencesA four-sided isolation fence is the best barrier as it completely surrounds the pool or spa. It is different from a property line or perimeter fence that keeps neighbors children from accessing your pool. Isolation fencing separates swimming pools or spas from the house. They are specially designed so that children cannot easily get over, under, or through them. Code compliant pool fences can be built from many different materials, but some are better suited to the task than others.

Aluminum FencesAluminum is a lightweight, low maintenance fencing material that is an excellent choice for pool fencing because of its physical attributes; it is strong and will not rust.

Steel FencesSteel is a sturdy fencing material that is a popular option for pool fencing. The look and feel of steel fencing closely matches that of aluminum, but it is heavier and stronger. When choosing steel fencing, make sure to choose a product with a high quality coating that will protect your fence from rust.

Wood FencesWood can be used to make a secure pool fence in either picket style or privacy style. Wood is relatively inexpensive when compared to aluminum, composite, and steel fencing. However, wood is higher maintenance than other materials, requiring periodic painting or staining.

Composite FencesComposite fences feature the look and feel of natural wood but without the maintenance. A premium fence material, composites not only offer protection, but can enhance the visual appeal of your property. Composite fences are a component system created from boards, rails, and posts, so they can be designed to meet local and national pool codes.

Chain Link FencesChain Link is an extremely affordable, low maintenance fence material. Made from galvanized steel tubing and a mesh of steel wire, chain link is strong, durable, and secure. Chain link can also be an effective privacy fence with the addition of privacy slats. One drawback of chain link fence is its industrial look and feel, which may be an issue if you are looking for a pool fence that also adds to the visual appeal of your property.

Vinyl FencesVinyl is an attractive, low maintenance fencing material that comes in a wide variety of styles and colors. Slightly more expensive than wood, vinyl fence eliminates the need for staining and painting, and has a long life span.

Perimeter FencesPerimeter fencing encloses a backyard pool but allows ready access through the house. It reduces drowning risk for children by 17 percent or less. It is better than no fencing for risk reduction, but children usually have no problem letting themselves into a backyard from the house interior. If you choose to install perimeter fencing, you should also have an alarm on the door in case a small child gains access to the pool area without adult supervision.

Removable Pool FencingRemovable Pool Fencing is a popular choice of many pool owners. This fence, made of mesh material, is left in place when there is a possibility of access to the swimming pool by young children, but removed when adults are present or for parties. It can be rolled up and stored away during occasions when a barrier is not needed. This mesh fencing has a transparent nature allowing you to have a clear view of the pool at all times. The only drawback to having this type of fencing is that it does not meet compliance codes for backyard safety in all areas. A pool professional can provide information for your specific area.

Pool Safety NetsPool safety nets provide a safe, secure barrier while maximizing the available backyard space and preserving the view and ambience of the swimming pool area.The size of the net's squares are the foundation of its safety pontential. The squares are small enough that children can't fall through, but too big to walk or stand on. One adult can remove or replace a typical swimming pool net in just a few minutes. A series of pulleys is built into the center of the pool net. By loosening the pulley rope, the tension is released and the pool net is easily removed. Just unhook the clips and roll the pool net onto the portable roller. Simply reverse this process to place the pool net back onto the pool. The safety pool net utilizes custom hooks and flush brass anchors in the deck to secure the net.As with all safety barriers the net is only to be used as deterrent and the child should never be left alone near the pool.Swimming pool nets provide an excellent barrier for small or confined areas. Finding a cover for uniquely shaped pools with rocks, waterfalls, raised planters, etc, can often be prohibitive, but they usually pose no problem for pool nets.A swimming pool net has several advantages over pool fences. Children cannot climb over or under a net pool cover like they may be able to with some fences. If unwanted pool entry by older children who may be able to gain access even though a fence is in place is a concern, a pool net can be a viable solution. A swimming pool net can be removed in about 5 minutes and replaced in 5 to 10 minutes.

Safety Pool CoversOne of the most crucial safety devices that a pool owner should have is a safety pool cover. Note that a winter pool cover and solar pool covers are NOT safety covers. To be a safety pool cover, it is required that a pool cover be able to hold a minimum of 485 pounds per five square feet. Safety covers come in two varieties mesh and solid. Both types of safety covers are anchored to a deck with straps that pull the cover taut over the pool; the straps usually attach to stainless steel springs and are anchored to recessed brackets in a deck surface. When the cover is removed, deck brackets that are not already flush with the deck can be screwed down to prevent tripping or toe-stubbing. Because the straps need to be anchored down, mesh covers generally require at least two to three feet of decking all around the pool. There are a variety of deck anchors for all types of decking material including, but not limited to, concrete, brick, asphalt, earth, and wood.

Mesh Safety Pool CoversMesh safety pool covers are designed for long-term use, such as when closing swimming pools for winter. Mesh safety pool covers require little maintenance because debris that lands on them blows off the top, and rain and snow drain through the mesh panels; however, with the screen-like material of mesh, some silt and dirt may get through the webbing. On the other hand, because puddles cannot accumulate on the surface, having a mesh-style safety pool cover eliminates the risk of toddlers or pets unexpectedly coming in contact with shallow water.

Solid safety pool coversSolid safety pool covers work similarly to mesh covers in that they can be secured to a deck by anchors. Solid safety pool covers may not be best for use in areas that receive heavy rain or snowfall. Unlike mesh covers that allow water to drain through the cover, precipitation can accumulate on a solid cover, creating a puddle of water over the pool. The collected water may tend to sag the cover and present a hazard to any small children or pets who, if unsupervised, wander onto to pool cover. To combat this problem, some manufacturers incorporate drain panels into solid vinyl covers. Small cover pumps that automatically pump water off the cover as soon as it is detected may also be used.

Pool AlarmsThere are many different types of pool alarms to consider depending on your budget, type of pool, and technical requirements. Remember that pool alarms are one tool that will help to make your swimming area safer. Parental guidance and vigilance are primary in insuring pool safety.

Gate alarmsGate alarms are mounted directly on your pools gate with two magnetic switches. These alarms, which are battery powered, activate when the gate is opened and the electrical field is broken. There is an override button that can be pressed by an adult to allow them to pass through without sounding the alarm. Gate alarms are designed for outdoor use, come in many different sizes, are inexpensive, and easy to install.

Door alarmsDoor alarms are designed for swimming pools that include the house in some part of their entire perimeter. When the door is opened an audible alarm sounds. These alarms, which are turned on and off using a key or a keypad, are either battery powered or use the homes current. They are affordable; easy to install, and provide a warning if the door is opened. They are also useful in detecting intruders.

Window AlarmsAs with door alarms, window alarms are used if the house is included in some part of or in the entire perimeter of the pool. When the window is opened, an audible alarm sounds. These alarms, which are turned on and off using a key or a keypad, are either battery powered or use the homes current. They are affordable, easy to install, and provide a warning if the window is opened.

Perimeter AlarmsPerimeter alarms use laser or infrared light, forming an unbroken beam of light around the swimming pools perimeter. When someone entering the perimeter breaks the beam, the alarm sounds. Alarm beams are positioned 12 to 24 inches above ground level and should be adjusted according to your childs height. These devices, which are the most expensive on the market, give total perimeter protection at a set height. Disadvantages are that the set height may not suit visiting children and that the alarm will activate if one of the pools perimeter alarms is inadvertently hit, moved, or covered.

Wrist AlarmsWrist alarms are the latest in water safety. They may be used at the pool or even in a boat. These waterproof devices are key locked securely onto your childs wrist and communicate via a base station. When the wrist alarm is immersed in water the station alarm is activated. Base units and wrist alarms are purchased separately, which means you may have numerous wrist alarms for one base station.

Floating/wave SensorsFloating/wave sensors are mounted on the edge of the pool or in the pool. They are key activated, battery powered, and portable. Generally these alarms sense water displacement when an object weighing more than fifteen pounds enters the pool. When this occurs, a signal is sent to a remote receiver which is either in the home or carried by the adult. The receiver emits an alarm of approximately 85 decibels. These alarms can be used with pool covers or solar blankets and have an adjustment that can reduce their sensitivity.

Fence/wall Mounted Passive Infrared Motion DetectorsFence/wall mounted passive infrared motion detectors are an all weather-designed system and may be mounted on a pool fence or wall. They can also be installed in a spa, patio, or garage. They protect an 8-yard semi circular area by emitting a 110-decibel alarm that can be heard up to 50 yards away. These alarms, which are most effective when mounted on a pool fence or wall, are armed one minute after being switched on and possess a 5 second entry delay feature which prevents the device from going off immediately after its been activated. Unique features include both a movement and heat sensitive sensor that can only be activated by a small child or animal when performing movements and emitting body heat within its patrol range.

Pool Mounted Passive Infrared Motion DetectorsPool mounted passive infrared motion detectors combine all of the important features found in other devices and are very affordable. Each unit simultaneously detects both motion and heat of anyone passing by and will not give any false readings for inanimate objects. With this device, a perimeter fence is not an integral part of the system as it is with most other systems. This key operated unit runs on batteries or a DC power adapter and has a 24-hour warning signal for low battery power. With a 110-decibel micro siren this is also the loudest alarm on the market and can be heard 50-yards away. These alarms cover an 8.5-yard radius and a 150-degree area.

Above Ground Pool AlarmsAbove Ground Pool Alarms use a new sensing method that requires no adjustments and is designed to detect intrusions similar to a 1- year old child weighing 18 pounds and up. The alarm is activated with an on/off key - simply remove the key to turn the alarm on. Entry into the pool by children, pets, or intruders is detected by the unit's electronic sensor, and sets off a loud, pulsating alarm both in the home and at the pool. The in-house remote receiver has a range up to 200 ft., and comes with a 12-volt power supply. Safe, simple, and easy to operate, the alarm snaps onto the top rail of your above ground pool. To store your alarm while using the pool, snap it on the outside of the pool.

Anti-Entrapment EquipmentSuction entrapment can occur when a swimmer gets pulled down by the suction of a pool or hot tub drain. If this happens, the victim can get their hair, limbs, or other body parts trapped and pulled toward the drain. The enactment of the Virginia Graeme Baker Pool and Spa Safety Act resulted over concern in a rise in serious injuries and drowning deaths by being entrapped by the suction of swimming pool drains and spas. Tragically, the Act is named after the seven year-old granddaughter of former Secretary of State James A. Baker, III, who died when she became entrapped by a hot tub drains suction.A Safety Vacuum Release System or SVRS for short is an automatic suction force release system. When a drain becomes blocked, the SVRS provides a rapid vacuum release. This quickly frees anyone whose body or limb is trapped on the drain. An SVRS works whether or not there is a cover on the drain, and does not interfere with the pump function. Once installed, an SVRS requires little or no maintenance. It is recommended to have a pool professional install the SVRS.A pool safety drain cover works to prevent the powerful suction of a pool drain from making a complete seal that could trap a person's body against the drain, or entangle hair, possibly resulting in drowning. Safety drains cover the main drain of a pool, which is the suction outlet at the bottom or side of a pool that conducts water to a recirculating pump. All pools are now required to be compliant with the Virginia Graeme Baker Pool and hot tub Safety Act, which became effective on December 19, 2008. The law is designed to improve child safety by requiring that all pools and spas have drain covers compliant with the American Society of Mechanical Engineers and American National Standards Institute. To meet the requirements of the new federal law, a main drain should now have a cover, a mounting frame, a sump (the small pit below the drain that receives drainage and channels it to the outlet pipe) and fasteners to make sure the drain cover is attached securely to the sump.

Handicap Accessible Pool Safety ProductsWater is a great source of therapy. It's floating properties, calming qualities, and relaxing maneuverability restores agility, develops strength, and improves circulation. Therefore, a lot of pool safety equipment is specially designed to accommodate injured, disabled, or elderly persons so that everyone can enjoy the curative powers of water.

Pool LadderOften the main safety issue with an injured, disabled or elderly swimmer involves safe entry and egress. Therefore, the most common solution is a lift. A lift can be added to the side of an inground pool, above ground pool, or spa. Starting May 15, 2012, all public swimming pools in the U.S. must be equipped with assisted entry systems. When this American Disability Association (ADA) compliance law takes effect next May, disabled Americans around the nation will be able to enjoy the health and leisure benefits of public pools. As part of the 2010 Standards for Accessible Design, regulations of the Accessible Design for Recreational Facilities will require all public pools and spas to be outfitted with an ADA compliant swimming pool lift or sloped entry.

Pool Access Ladders and rampsPortable access ladders act as an easy-to-use staircase that can be attached anywhere along the edge for effortless entry or exiting. They also come with a deck adapter platform, side skirting to prevent underwater entrapment and dolly. The staircase consists of slip-resistant tread steps. Multi-purpose disability access ramps consist of a ramp, stair and underwater parallel bars. It can easily be removed from the pool making room for automatic cleaners and pool covers.

General Pool Safety ProductsWith the right swimming pool safety products, you can reduce the risks and dangers inherent to swimming pools and, at the same time, make your pool environment a more enjoyable place for everyone.Swimming pool and hot tub hand rails and stair rails provide an extra protection against slipping on stairs and steps.Pool signs and depth markers are also extremely important to have in the pool area. These pool depth markers can be applied to vinyl, ceramic tile and tempered glass overlays. Signs that should be in your pool area can include No Jumping, No Diving, Shallow Water and Slippery When Wet.You should also have basic safety equipment available such as lifesaver rings and a Shepherds Crook.

ADA STANDARDS FOR SWIMMING POOLSPool RampThere are over 50 million people with disabilities in the United States, which equates to 18% of the population making persons with disabilities the largest minority group. To protect this population, the Americans with Disabilities Act (ADA) was designed to prevent discrimination against a person based on a disability. The goal of the ADA is to provide a level playing field so that a person with a disability can compete equally for jobs and also enjoy the same benefits of living in the United States as a person who is able-bodied.As part of the legislation passed by the ADA, over 100,000 commercial swimming pools will be required to become accessible to people with disabilities by March 15, 2012. Generally, this legislation will only affect state and local government owned facilities, parks and recreation departments, state run schools and universities, as well as hotels, health clubs, private schools and community centers. Private residences, apartments and condominiums are not affected, with a few exceptions:If an apartment complex sells memberships to their pool to people living outside the complex, the pool IS considered public and is subject to the ADA regulations.

If a condominium actively rents out their units, similar to a hotel, this is also considered a public accommodation and subject to ADA regulations.ADA regulations affect several types of aquatic areas. These include swimming pools, spas, wading pools and other aquatic recreation facilities such as wave pools and lazy rivers. Beaches, lakes, rivers and catch pools are NOT affected by the new ADA legislation. Means of access will need to be provided to the types of aquatic areas affected by the legislation.The newly adopted regulations define five permitted means of access for swimming pools, including:

Swimming Pool LiftsPrimary means of access that is a mechanical device used to transfer an individual in and out of a swimming pool. These lifts can be battery or water pressure powered.

Sloped entriesPrimary means of access that is ideal for facilities with a large group of ambulatory users. A sloped entry can be a built-in entryway or a removable ramp. Facilities that use sloped entries as a means of access are also encouraged to provide a mobile aquatic chair designed for access into the water.

Transfer WallsA secondary means of access that allows someone to transfer onto the top of the pool wall from a wheelchair and ease into the water. At least one grab bar should extend the width of the top of the pool wall. This type of access is typically used in spas.

Transfer SystemsThis secondary type of access allows someone to transfer from a wheelchair to the top of the system and transfer down the device, much like a transfer wall. A grab bar must be provided for this device.

Accessible Pool StairsThis secondary type of access provides balance and support for someone entering the pool from a standing position.Access requirements differ depending on the size of the swimming pool. For large pools with over 300 linear feet of pool wall, two means of access are required. One of these MUST be a primary access. For smaller pools with under 300 linear feet of pool wall, at least one means of access must be provided, and it MUST be primary.Tax credits are also available to ease the financial burden associated with implementing these new regulations. If a facility has annual revenue under $1 million or has fewer than 30 employees, it can receive a tax credit up to $5000 to help offset the cost of the accessibility modifications.