When it relates to purchasing a pool in Nemo , many people must decide whether they would like an in-ground pool or an above ground pool. While both types of pools are popular, many people would opt for to have an in-ground pool. The only problem with in-ground pools is that they are regularly costly to afford. That signifies that if you’re the owner of an in-ground pool, it is probable that you would want to have the most out of your investment.
Best Swimming Pool Design In Rapid City
This can be achieved by equipping your pool with popular pool accessories.When it relates to pool accessories in Nemo , there are a broad variety of different items that are viewed accessories. These things earn the name accessory because they are not included with the acquire of a pool; therefore, they has to be purchased on an individual basis. Irrespective of the fact that pool accessories require spending extra money, it is likely that you will like having them. The reason for this is there are literally an unlimited number of accessories to select from. With a selection so wide, you are likely to find precisely what you would like or need.When many individuals think about pool accessories, pool toys often come to mind. Currently, there are a huge number of pool toys that are accessible obtainable. Over and over, these toys are classified into two different categories. These categories are regularly affordable pool toys and expensive ones. If you’re searching for low-cost pool toys, you are not alone. Many pool owners enjoying having pool toys, but many don’t want to expend a huge amount of cash on them. If this is the situation, you may want to look into obtaining beach balls, swim rings, dive sticks, and other similar toys. Most of these matters can be obtained for fewer than.If price is not an issue, you may wish to stare into more expensive pool toys.
Jump to navigation Jump to search Below ground, outdoor pressure side automated pool cleaner visible at bottom The first patented cistern cleaner, the forerunner of the swimming pool cleaner 2012 was the Centennial anniversary of the first swimming pool cleaner R.B. Everson invented the first suction-side pool vacuum cleaner in 2002 the first handheld/extended reach, battery-powered pool and spa vacuums were finally invented. They now come in many sizes for all applications Typical electric robotic pool cleaner Weda B480 robotic commercial pool cleaner for the largest public pools. They now come in many smaller sizes from several manufacturers with a wide array of sophisticated, computerized programs An automated pool cleaner is a vacuum cleaner intended to collect debris and sediment from swimming pools with minimal human intervention. Popularly dubbed a ''creepy-crawly'' or "Kreepy Krauly" in South Africa, it is one of several types of swimming pool vacuum cleaners. Other major types are battery-powered or manually powered wands effective only for very small pools, kiddie or wading pools and small spas and hot tubs, and battery-powered, handheld/extended reach pool and spa vacuums. The latter are powered by rechargeable batteries and can be hand held attached to a telescopic pole used for extended reach. These are used for small to medium-sized pools, larger spas, and to spot clean larger pools. The name ''creepy-crawly'' derives from the vacuum's webbed-nozzle crawling creepily through the underwater mist as well as for its creepy suction noise. ''Creepy crawly'' originally referred to strange creatures that crawl on the bottom of the ocean, as the webbed nozzle of the vacuum slightly resembles an octopus in both appearance and suction ability. Swimming pool cleaners evolved from two areas of science: development of the water filter and early cistern cleaners. The forerunner of today's pool cleaners were cistern cleaners. A cistern (Middle English cisterne, from the Latin cisterna, from cista, box, from Greek kistê, basket) is a waterproof receptacle for holding liquids, usually water. Often cisterns were and still are built to catch and store rainwater. The great palaces of antiquity had both lavish pools and cisterns. They were prevalent in early America as well. United States Patent and Trademark Office makes reference to a cistern cleaner patent filed (though never issued) as early as 1798. Before swimming pools were affordable and fashionable, many swam in their larger cisterns. In 1883 John E. Pattison of New Orleans filed an application for a "Cistern and Tank Cleaner " and the first discovered patent was issued the following year. It swept and scraped the bottom of a cistern or tank, and through a combination of suction and manipulation of the water pressure was able to separate and remove sediment without removing the water. Over the next 20 years his invention was improved on numerous occasions. Many pool cleaner patents issued in the modern era refer to some of the cistern cleaners as predecessors of their invention. The first swimming pool cleaner was invented in 1912 by Pittsburgh, Pennsylvania local citizen John M. Davison. On November 26, 1912, he submitted a patent application to the United States Patent and Trademark Office entitled "Cleaning Apparatus For Swimming Pools And The Like," patent number 1,056,779 that was issued on March 25, 1913. The first suction-side pool cleaner was invented by Roy B. Everson of Chicago in 1937, which he entitled "Swimming Pool Cleaner". Nineteen years later, the first suction-side pool cleaner was the work of Joseph Eistrup of San Mateo, California, who called his invention simply "Pool Cleaner". Two years later, the first truly automatic, aptly named "Automatic Swimming Pool Cleaner" was created by Andrew L. Pansini of Greenbrae, California, founder of the industry icon Jandy Corporation. Patent Number 3,032,044 was touted by Pansini as "an automatic swimming pool cleaner", which is effective to remove the scum, dirt and other accumulations from both the bottom and side walls of a pool to disperse foreign matter in the, water for removal therefrom by normal pump-filter system of the pool. The first robotic pool cleaner that used electricity was the work of Robert B. Myers of Boca Raton, Florida in 1967, who filed a patent. The third and last of the generally accepted pool cleaner technologies, the pressure-side cleaner, was invented by Melvyn L. Henkin of Tarzana, California in 1972. His "Automatic Swimming Pool Cleaner, United States Patent Number 3,822,754 utilized three wheels to allow the machine "to travel underwater along a random path on the pool vessel surface for dislodging debris therefrom". The design is probably familiar to pool owners as the Polaris Pool Cleaner. Independently from his American counterparts Ferdinand Chauvier invented the Kreepy Krauly in South Africa in 1974 in Springs. There are three main types of automated or automatic swimming pool cleaners, classified by the drive mechanism and source of power used: In this type, water pumped out of the pool via its skimmer or drains is used for locomotion and debris suction and returned after being filtered via pool return or outlet valves. This is the least expensive and most popular type. It traces a random course. This type of cleaner is usually attached via a 1.5 inch hose to a vacuum plate in the skimmer, or to a dedicated extraction or "vac" line on the side of the pool. The suction action of the pool's pump provides motive force to the machine to randomly traverse the floor and walls of the pool, extracting dirt and debris in its path. The first automatic pool cleaner was a suction cleaner. These are the least expensive and most widely used pool cleaners with purchase costs ranging in the $100–$300 price range. They are powered solely by the main pump of the pool and utilize the pool's filter system to remove dirt and debris from the water. These machines effectively diminish the suction of the main pump - using them will increase the electricity costs and require the main pump and filter system to be serviced more frequently. There is minimal maintenance and part replacement costs on these devices over time. In this design, pool water inflow is further pressurized using a secondary "booster" pump on most but not all models. This high-pressure water is used for locomotion and debris suction, employing the venturi effect. It traces a random course. The requirement of a booster pump makes this type the highest in electricity use of the three types of pool cleaners. The pressure causes turbulence in the water, distributing some debris on the floor and walls of the pool, some of which is re-floated to the pool surface and then sucked into the main filter through the skimmer inlets. A portion of the dirt and debris is caught in an attached filter bag. The purchase cost of this type of cleaner range from a minimum of $200 to about $700 plus the costs of the booster pump, usually over $200. Some more sophisticated models can cost over $1,000. Both suction-side and pressure-side cleaners are dependent on the pool's main pump and filter system to remove contaminants from the pool water, so cannot remove particles smaller than the pore size of the pool's existing filter element. Such elements can be made of sand, diatomaceous earth, zeolite or other natural or synthetic materials. That particle size ranges from under 5 µm for diatomaceous filters to well in excess of 50 µm for sand filters. Disadvantages of these types of pool cleaners are the additional electricity use, and filtration limitation by the pore size of the main filter element, as well as the time and effort needed to attach the device to the ports that connect to the main pump and filter, and the increased burden of maintenance time and expense on the pool's mechanics. These cleaners are independent from the pool's main filter and pump system and are powered by a separate electricity source, usually in the form of a set-down transformer that is kept at least 10 feet (3.0 m) from the water in the pool, often on the pool deck. They have two internal motors: one to suck in water through a self-contained filter bag and then return the filtered water at a high rate of speed back into the pool water. The second is a drive motor that is connected to tractor-like rubber or synthetic tracks and "brushes" connected by rubber or plastic bands via a metal shaft. The brushes, resembling paint rollers, are located on the front and back of the machine and help remove contaminating particles from the pool's floor, walls (and in some designs even the pool steps) depending on size and configuration. They also direct the particles into the internal filter bag. An internal microchip is pre-programmed to turn on and off and reverse the direction of the drive motors. The chip will cause the machine to change direction when it reaches a wall or the water surface after climbing the pool walls. These machines may also be directed by sensors located in the bump bars which, on contact with objects such as a wall, cause a reverse in direction, with a small offset allowing it to move one machine's width over on each crossing of the pool. The delay timer is an important feature for many pools, as many switch off a number of circulation pumps during the night to allow suspended particles to settle on the bottom of the pool; after a couple of hours the pool cleaner begins its cleaning cycle. This cleaning cycle is set up to complete before the pumps are turned back on. Though not necessary for adequate pool cleaning, this feature saves energy and improves cleaning efficiency. In order to move forward and backward and negotiate walls and steps electric robotic cleaners rely on three natural principles, traction and movement caused by the drive motor and tracks, buoyancy created by the large areas inside the machine that fills with air, and the force resulting from the high pressure of water being emitted from the top of the machine that pushes it against the floor and walls. Some electric robotic machines use brushes made out of polyvinyl alcohol (PVA) Polyvinyl alcohol that has an adherence quality that allows the unit to almost cling to the walls, steps and floors. They also are resistant to dirt and oil improving lifespan over rubber or other synthetic materials. The combination of these three natural principles along with an internal mercury switch that tells the microchip that the unit has gone from a horizontal to vertical position as it climbs a wall allows it to change direction from ascending to descending the wall at pre-programmed intervals based on the average height of a pool walls. Some machines have delayed timers that cause the robot to remain at the water line, where more dirt accumulates, for momentarily resulting in a scrubbing action, much like the wheels of a powerful automobile spinning or peeling out. The major benefits of these machines are efficiency in time, energy, and cleaning ability as well as low maintenance requirements and costs. The major disadvantage is purchase cost which can range from $500 for floor-cleaning-only machines to over $2,000 for the most sophisticated residential units. According to P.K. Data of Duluth, a Georgia consulting and market research firm that has been retained for many years by the pool and spa industry's internal trade organization, The Association of Pool & Spa Professionals (APSP) there are approximately 14,000,000 residential pools and spas in the United States and over 400,000 commercial or public pools. As a result, this has created a market for larger, more powerful commercial pool cleaners. All commercial pool cleaners are electric robotic and can range in price from a little over $1,000 to upwards of $15,000 or more. They closely resemble residential models but in addition to their addition size they are made with heavy duty components and often more sophisticated computer guidance and on and off systems. There have been attempts for nearly 100 years to mandate the use of pool cleaners, primarily addressed to public pools. Currently the Center for Disease Control and Prevention located in the Greater Atlanta, Georgia metropolitan area on a grant provided by the National Swimming Pool Foundation (NSPF) is about to publish the first uniform Model Aquatic Health Code (MAHC). Included is a section on pool filtration proposed regulations directed to the nation's 3200+ state and local agencies that enforce laws and ordinances relating to the operation of swimming pools and spas. The proposed MAHC is not the first attempt to propose a uniform aquatic health code. The credit for that goes to the American Public Health Association(APHA) which 100 years ago recognized the dangers of improperly maintained aquatic facilities and formed a committee in 1918 that, for the next 66 years, issued eleven so-called "Swimming Pools and Other Public Bathing Places Standards For Design, Construction, Equipment And Operation" recommended ordinances and regulations. But for a variety of reasons none of these recommendations were adopted, at least not formally or completely adopted. The APHA has tried to develop a uniform aquatic health code, or what it referred to for years as referenced above, and published short reports annually from 1920 through 1925 that it simply referred to as "Report of the Committee On Bathing Places". and finally in 1926  published in its journal its first comprehensive report it called "Standards for Design, Construction, Equipment and Operation" for "Swimming Pools and Other Public Bathing Places". Twelve others were published through 1981. However, its lack of authority to enforce them is implied by the changing description of what was limited to their recommendations or suggestions and the expressed purposes in issuing them. In 1912, coincidentally the same year when the United States Patent and Trademark Office issued the first patent for a swimming pool cleaner, the Sanitary Engineering Section of the American Public Health Association (APHA) convened in New York City to lay the groundwork for the first recommended pool and spa regulations. As reported in the American Journal of Public Health in April 1912 a meeting was held in Havana the previous December and at the New York meeting among the subjects that the committee was to be studying was "Hygiene of swimming pools". Six years later a committee on swimming pools was appointed at the APHA's annual meeting in Chicago and in 1920 a similar committee was appointed at the meeting in Washington, D.C. In 1921 and periodically over the next seven decades until the work of the APHA on this subject matter went through a series of divisions and consolidations, diverted elsewhere its committees and joint committees with other health-orientated public and quasi-public organizations issued proposed ordinances and regulations in the form of unenforceable recommendations. Despite their intended and published goals, none became law, uniform, much less national. None of the proposed Standards included more than a passing reference of the need to properly clean a pool. A few, but curiously not all of these recommended ordinances and regulations, related to the use of a vacuum, although the first that included any specificity in 1923 at least required a certain level of clarity. The 1921 report, barely a few pages in length, made this reference to the need to clean the pool. Pool cleaning is done by completely emptying the pool an average of twice weekly and scrubbing with stiff brushes and soap. Hose flushing follows the scrubbing. After the flushing outlet is opened, the well turned on and clean water allowed to water over the floor of the drains, etc... The 1923 report of the American Journal of Public Health, Sanitary Engineering Section American Public Health Association read before the Sanitary Engineering Section of the American Public Health Association at the Fifty-second Annual Meeting at Boston, Massachusetts, October 8, 1923. slightly longer, but still very brief stated: Section 3. Clearness: At all times when the pool is in use the water shall be sufficiently clear to permit a black disk six inches in diameter on a white filed, placed on the bottom of the pool at the deepest point, to be clearly visible from both sides of the pool when the water is quiet. It further stated: No swimming pool shall be opened to the use of bathers on any day until all visible dirt (not stains) on the bottom of the pool and any visible scum or floating matter on the surface has been removed. Scum and floating matters may be infectious material and should always be removed as soon as possible after they are observed. Therefore, in 1921 it was recognized that infectious material, namely pathogens collect in the pool and should be removed. It was not until 1926 twelve years after the organization recognized the need to address swimming pool "hygiene" and eight years after the committee was organized that the first true report was issued and later published in the Journal of the American Public Health Association. Of all of its reports from 1920 through 1981 the first major report by the APHA the 1926 one, written in narrative form as were the succeeding nine ones though 1957 the committee included the detailed provisions relating to pool cleaning, vacuuming and vacuums: E. Suction Cleaner: In the opinion of the committee the only satisfactory method of removing the dirt, hair, etc., settling on the bottom of a pool is by means of a suction cleaner. As such cleaners are commonly operated by the circulation pumps; they may be classed as an adjunct to the recirculation system. When a suction cleaner is to be operated by the recirculation pump, a gate with graduated stem or other registering device should be provided for throttling the flow from the pool outlet to permit the pump to operate at maximum efficiency when the suction cleaner is in use. Fixed pipe connections for attachment of suction cleaner to pump suction should be of ample size to reduce friction to a minimum and the cleaner and all removable connections should be designed to provide a maximum velocity at the suction nozzle. XXVI Cleaning Pool A. Visible dirt on the bottom of a swimming pool shall not be permitted to remain more than 24 hours. B. Any visible scum or floating material on the surface of a pool shall be removed within 24 hours by flushing or other effective means The 1964 report included the following language: A vacuum-cleaning system shall be provided. When an integral part of the recirculation system, sufficient connections shall be located in the walls of the swimming pool, at least eight inches below the water line and "Visible dirt on the bottom of the swimming pool shall be removed every 24 hours or more frequently as required. Visible scum or floating matter on the swimming pool surface shall be removed within 24 hours by flushing or other effective means. The CDC was founded (in 1946), followed by the Cabinet-level Department of Health, Education and Welfare (in 1953), now the Department of Health, and Human Services and its 11 operating divisions, the National Health Service Corps (in 1977) and along the way a variety of private and non-profit aquatic organizations such as the National Spa and Pool Association (in 1956), now the Association of Pool and Spa Professionals the National Swimming Pool Foundation (in 1965). Presently a variety, but not by a long shot the majority, of states and jurisdictions that have codified the requirement of inclusion of an independent vacuum cleaner including the two states with the highest number and concentration of both residential and public pools: California: 2010 Title 24, Part 2, Vol. 2 California Building Code. Section 3140B, Cleaning Systems: A vacuum cleaning system shall be available which is capable of removing sediment from all parts of the pool floor. A cleaning system using potable water shall be provided with an approved backflow protection device as required by the California Department of Public Health under Sections 7601 to 7605. —  Florida: Florida Department of Health section 64E-9.007 Recirculation and Treatment System Requirements (12) Cleaning system – A portable or plumbed in vacuum cleaning system shall be provided. All vacuum pumps shall be equipped with hair and lint strainers. Recirculation or separate vacuum pumps shall not be used for vacuuming purposes when in excess of 3 horsepower. When the system is plumbed in, the vacuum fittings shall be located to allow cleaning the pool with a 50 foot maximum length of hose. Vacuum fittings shall be mounted no more than 15 inches below the water level, flush with the pool walls, and shall be provided with a spring loaded safety cover which shall be in place at all times. Bag type cleaners which operate as ejectors on potable water supply pressure must be protected by a vacuum breaker. Cleaning devices shall not be used while the pool is open to bathers. —  In 2005 the CDC in response to a growing concern and feared epidemic with the pathogen Cryptosporidium the Center for Disease Control Center for Disease Control, much like the American Public Health Association did in 1912 convened many of the country's foremost medical and other scientific experts to study the concern for aquatic health. As a result, in 2007 they began their quest, again much like the APHC for a uniform aquatic health code. Each health and safety segment has been assigned to a committee to study it and draft a proposed module open for public comment before being adopted and then recommended to the nation's 3200+ state and local health agencies that enact ordinances and regulations for swimming pools and spa and other aquatic facilities, inspect and monitor them and then enforce the regulations. Since the focus of the MAHC was to respond to the threat of Cryptosporidium the Technical Committee of Recirculation Systems and Filtration is a major focus. The University of North Carolina Charlotte Associate Professor James Amburgey is the Chairperson of the Center For Disease Control, Model Aquatic Health Code Technical Committee on Recirculation Systems and Filtration. Amburgey has conducted many tests to evaluation existing swimming pool filters and his conclusions have been they are extremely ineffective in most cases to help remove Cryptosporidium. He is reported to be working with several manufacturers of swimming pool and spa vacuum cleaners to develop a filter bag that will result in exponential advancements in the current filter bags, cleaners and vacuums on the market.
Jump to navigation Jump to search Swimming pool sanitation is the process of ensuring healthy conditions in swimming pools. Proper sanitation is needed to maintain the visual clarity of water and to prevent the transmission of infectious waterborne diseases. Two distinct and separate methods are employed in the sanitation of a swimming pool. The consecutive dilution system to allow the removal of organic waste on a daily basis by using the sieve baskets inside the skimmer and circulation pump and the sand unit with a backwash facility for easy removal of organic waste from the water circulation. Disinfection normally in the form of Hypochlorous acid (HClO) to kill infectious microorganisms. Alongside these two distinct measures within the pool owners jurisdiction, swimmer hygiene and cleanliness helps reduce organic waste build up. The World Health Organization has published international guidelines for the safety of swimming pools and similar recreational-water environments, including standards for minimizing microbial and chemical hazards. The United States Centers for Disease Control and Prevention also provides information on pool sanitation and water related illnesses for health professionals and the public. The main organizations providing certifications for pool and spa operators and technicians are the National Swimming Pool Foundation and Association of Pool & Spa Professionals. The certifications are accepted by many state and local health departments. Swimming pool contaminants are introduced from environmental sources and swimmers. Affecting primarily outdoor swimming pools, environmental contaminants include windblown dirt and debris, incoming water from unsanitary sources, rain containing microscopic algae spores and droppings from birds possibly harbouring disease-causing pathogens. Indoor pools are less susceptible to environmental contaminants. Contaminants introduced by swimmers can dramatically influence the operation of indoor and outdoor swimming pools. Sources include micro-organisms from infected swimmers and body oils including sweat, cosmetics, suntan lotion, urine, saliva and fecal matter; for example, it was estimated by researchers that swimming pools contain, on average, 30 to 80 mL of urine for each person that uses the pool. In addition, the interaction between disinfectants and pool water contaminants can produce a mixture of chloramines and other disinfection by-products. The journal Environmental Science & Technology reported that sweat and urine react with chlorine and produce trichloramine and cyanogen chloride, two chemicals dangerous to human health.  Nitrosamines are another type of the disinfection by-products that are of concern as a potential health hazard. Acesulfame potassium is widely used in the human diet and excreted by the kidneys. It has been used by researchers as a marker to estimate to what degree swimming pools are contaminated by urine. It was estimated that a commercial-size swimming pool of 220,000 gallons would contain about 20 gallons of urine, equivalent to about 2 gallons of urine in a typical residential pool. Pathogenic contaminants are of greatest concern in swimming pools as they have been associated with numerous recreational water illnesses (RWIs). Public health pathogens can be present in swimming pools as viruses, bacteria, protozoa and fungi. Diarrhea is the most commonly reported illness associated with pathogenic contaminants, while other diseases associated with untreated pools are Cryptosporidiosis and Giardiasis. Other illnesses commonly occurring in poorly maintained swimming pools include otitis externa, commonly called swimmers ear, skin rashes and respiratory infections. Contamination can be minimized by good swimmer hygiene practices such as showering before and after swimming, and not letting children with intestinal disorders swim. Effective treatments are needed to address contaminants in pool water because preventing the introduction of pool contaminants, pathogenic and non-pathogenic, into swimming pools is impossible. A well-maintained, properly operating pool filtration and re-circulation system is the first barrier in combating contaminants large enough to be filtered. Rapid removal of filterable contaminants reduces the impact on the disinfection system thereby limiting the formation of chloramines, restricting the formation of disinfection by-products and optimizing sanitation effectiveness. To kill pathogens and help prevent recreational water illnesses, pool operators must maintain proper levels of chlorine or another sanitizer. Over time, calcium from municipal water tends to accumulate, developing salt deposits in the swimming pool walls and equipment (filters, pumps), reducing their effectiveness. Therefore, it is advised to either completely drain the pool, and refill it with fresh water, or recycle the existing pool water, using reverse osmosis. The advantage of the latter method is that 90% of the water can be reused. Pool operators must also store and handle cleaning and sanitation chemicals safely. Disease prevention should be the top priority for every water quality management program for pool and spa operators. Disinfection is critical to protect against pathogens, and is best managed through routine monitoring and maintenance of chemical feed equipment to ensure optimum chemical levels in accordance with state and local regulations. Modern digital equipment when used in conjunction with automatic chemical feeders results in stable pH and chlorine levels. Local jurisdiction may demand a wait time if chemicals are added by hand to the water so that swimmers are not injured. Chemical parameters include disinfectant levels according to regulated pesticide label directions. pH should be kept between 7.2-7.8. Human tears have a pH of 7.4, making this an ideal point to set a pool. More often than not, it is improper pH and not the sanitiser that is responsible for irritating swimmers' skin and eyes. Total alkalinity should be 80-120 ppm and calcium hardness between 200 – 400 ppm. Good hygienic behavior at swimming pools is also important for reducing health risk factors at swimming pools and spas. Showering before swimming can reduce introduction of contaminants to the pool, and showering again after swimming will help to remove any that way have been picked up by the swimmer. Those with diarrhea or other gastroenteritis illnesses should not swim within 2 weeks of an outbreak, especially children. Cryptosporidium is chlorine resistant. To minimize exposure to pathogens, swimmers should avoid getting water into their mouths and never swallow pool or spa water. Maintaining an effective concentration of disinfectant is critically important in assuring the safety and health of swimming pool and spa users. When any of these pool chemicals are used, it is very important to keep the pH of the pool in the range 7.2 to 7.8-according to the Langelier Saturation Index, or 7.8 to 8.2- according to the Hamilton Index; higher pH drastically reduces the sanitizing power of the chlorine due to reduced oxidation-reduction potential (ORP), while lower pH causes bather discomfort, especially to the eyes. However, according to the Hamilton Index, a higher pH can reduce unnecessary chlorine consumption while still remaining effective at preventing algae and bacteria growth. To help ensure the health of bathers and protect pool equipment, it is essential to perform routine monitoring of water quality factors (or "parameters") on a regular basis. This process becomes the essence of an optimum water quality management program. Conventional halogen-based oxidizers such as chlorine and bromine are convenient and economical primary sanitizers for swimming pools and provide a residual level of sanitizer that remains in the water. Chlorine-releasing compounds are the most popular and frequently used in swimming pools whereas bromine-releasing compounds have found heightened popularity in spas and hot tubs. Both are members of the halogen group with demonstrated ability to destroy and deactivate a wide range of potentially dangerous bacteria and viruses in swimming pools and spas. Both exhibit three essential elements as ideal first-line-of-defense sanitizers for swimming pools and spas: they are fast-acting and enduring, they are effective algaecides, and they oxidize undesired contaminants. Swimming pools can be disinfected with a variety of chlorine-releasing compounds. The most basic of these compounds is molecular chlorine (Cl2); however, its application is primarily in large commercial public swimming pools. Inorganic forms of chlorine-releasing compounds frequently used in residential and public swimming pools include sodium hypochlorite commonly known as liquid bleach or simply bleach, calcium hypochlorite and lithium hypochlorite. Chlorine residuals from Cl2 and inorganic chlorine-releasing compounds break down rapidly in sunlight. To extend their disinfectant usefulness and persistence in outdoor settings, swimming pools treated with one or more of the inorganic forms of chlorine-releasing compounds can be supplemented with cyanuric acid—a granular stabilizing agent capable of extending the active chlorine residual half-life (t½) by four to sixfold. Chlorinated isocyanurates, a family of organic chlorine-releasing compounds, are stabilized to prevent UV degradation due to the presence of cyanurate as part of their chemical backbone. Chlorine reacting with urea in urine and other nitrogen-containing wastes from bathers can produce chloramines. Chloramines typically occur when an insufficient amount of chlorine is used to disinfect a contaminated pool. Chloramines are generally responsible for the noxious, irritating smell prominently occurring in indoor pool settings. A common way to remove chloramines is to "superchlorinate" (commonly called "shocking") the pool with a high dose of inorganic chlorine sufficient to deliver 10 ppm chlorine. Regular superchlorination (every two weeks in summer) helps to eliminate these unpleasant odors in the pool. Levels of chloramines and other volatile compounds in water can be minimized by reducing contaminants that lead to their formation (e.g., urea, creatinine, amino acids and personal care products) as well as by use of non-chlorine "shock oxidizers" such as potassium peroxymonosulfate. Medium pressure UV technology is used to control the level of chloramines in indoor pools. It is also used as a secondary form of disinfection to address chlorine tolerant pathogens. A properly sized and maintained UV system should remove the need to shock for chloramines, although shocking would still be used to address a fecal accident in the pool. UV will not replace chlorine, but is used to control the level of chloramines, which are responsible for the odor, irritation, and enhanced corrosion at an indoor pool. Copper ion systems use a low voltage current across copper bars (solid copper, or a mixture of copper and zinc or silver) to free copper ions into the flow of pool water to kill organisms such as algae in the water and provide a "residual" in the water. Alternative systems also use titanium plates to produce oxygen in the water to help degrade organic compounds. An electrically operated water pump is the prime motivator in recirculating the water from the pool. Water is forced through a filter and then returned to the pool. Using a water pump by itself is often not sufficient to completely sanitize a pool. Commercial and public pool pumps usually run 24 hours a day for the entire operating season of the pool. Residential pool pumps are typical run for 4 hours per day in winter (when the pool is not in use) and up to 24 hours in summer. To save electricity costs, most pools run water pumps for between 6 hours and 12 hours in summer with the pump being controlled by an electronic timer. Most pool pumps available today incorporate a small filter basket as the last effort to avoid leaf or hair contamination reaching the close-tolerance impeller section of the pump. A pressure-fed sand filter is typically placed in line immediately after the water pump. The filter typically contains a medium such as graded sand (called '14/24 Filter Media' in the UK system of grading the size of sand by sifting through a fine brass-wire mesh of 14 to the inch (5.5 per centimeter) to 24 to the inch (9.5 per cm)). A pressure fed sand filter is termed a 'High Rate' sand filter, and will generally filter turbid water of particulates no less than 10 micrometers in size. The rapid sand filter type are periodically 'back washed' as contaminants reduce water flow and increase back pressure. Indicated by a pressure gauge on the pressure side of the filter reaching into the 'red line' area, the pool owner is alerted to the need to 'backwash' the unit. The sand in the filter will typically last five to seven years before all the "rough edges" are worn off and the more tightly packed sand no longer works as intended. Recommended filtration for public/commercial pools are 1 ton sand per 100,000 liters water (10 ounces avdp. per cubic foot of water) [7.48 US or 6.23 UK gallons]. Introduced in the early 1900s was another type of sand filter; the 'Rapid Sand' filter, whereby water was pumped into the top of a large volume tank (3' 0" or more cube) (1 cubic yard/200US gal/170UK gal/770 liters) containing filter grade sand, and returning to the pool through a pipe at the bottom of the tank. As there is no pressure inside this tank, they were also known as 'gravity filters'. These type of filters are not greatly effective, and are no longer common in home swimming pools, being replaced by the pressure-fed type filter. Some filters use diatomaceous earth to help filter out contaminants. Commonly referred to as 'D.E.' filters, they exhibit superior filtration capabilities. Often a D.E. filter will trap waterborne contaminants as small as 1 micrometer in size. D.E. filters are banned in some states, as they must be emptied out periodically and the contaminated media flushed down the sewer, causing a problem in some districts' sewage systems. Other filter media that have been introduced to the residential swimming pool market since 1970 include sand particles and paper type cartridge filters of 50 to 150 square feet (14 m2) filter area arranged in a tightly packed 12" diameter x 24" long (300 mm x 600 mm) accordion-like circular cartridge. These units can be 'daisy-chained' together to collectively filter almost any size home pool. The cartridges are typically cleaned by removal from the filter body and hosing-off down a sewer connection. They are popular where backwashed water from a sand filter is not allowed to be discharged or goes into the aquifer. Automated pool cleaner Automated pool cleaners more commonly known as "Automatic pool cleaners" and in particular electric, robotic pool cleaners provide an extra measure of filtration, and in fact like the handheld vacuums can microfilter a pool, which a sand filter without flocculation or coagulalents is unable to accomplish  These cleaners are independent from the pool's main filter and pump system and are powered by a separate electricity source, usually in the form of a set-down transformer that is kept at least 10 feet (3.0 m) from the water in the pool, often on the pool deck. They have two internal motors: one to suck in water through a self-contained filter bag and then return the filtered water at a high rate of speed back into the pool water. The second is a drive motor that is connected to tractor-like rubber or synthetic tracks and "brushes" connected by rubber or plastic bands via a metal shaft. The brushes, resembling paint rollers, are located on the front and back of the machine and help remove contaminating particles from the pool's floor, walls (and in some designs even the pool steps) depending on size and configuration. They also direct the particles into the internal filter bag. Saline chlorination units, electronic oxidation systems, ionization systems, microbe disinfection with ultra-violet lamp systems, and "Tri-Chlor Feeders" are other independent or auxiliary systems for swimming pool sanitation. A consecutive dilution system is arranged to consecutively remove organic waste that has been skimmed from the surface of the water. The surface water is pulled through the skimmer mouth where large organic waste is trapped inside the skimmer basket sieve. Each sieve basket reduces in mesh size to dilute the size of the contaminant as it passes through the consecutive dilution system. Dilution defines as the action of making something weaker in force, content, or value. The second consecutive sieve basket is attached to the circulation pump. Here the 25% of water drawn from the main drain at the bottom of the swimming pool meets the 75% of water drawn from the surface of the water. The circulation pumps sieve basket is easily accessible by the pool owner to be emptied daily. The third consecutive sieve is the sand unit. Here smaller organic waste that has slipped through the previous consecutive sieves is trapped by the sand. If not removed regularly the organic waste will continue to rot down and leech into the water. Through this dilution process it allows the organic waste to be easily removed via the sieve baskets and ultimately to be back washed to remove smaller organic waste trapped in the sand sieve to stop it leeching ammonia and other compounds into the recirculated water causing (DBP's). The sieve baskets are easily removed daily for cleaning as is the sand unit which should be back washed at least once a week. With a perfectly maintained consecutive dilution system the build up of Chloramines and other disinfection bye products(DBP's) can be drastically reduced. The water returned to the pool should have been sieved of all organic waste above 10 microns. Water is typically drawn from the pool via a rectangular aperture in the wall, connected through to a device fitted into one (or more) wall/s of the pool. The internals of the skimmer are accessed from the pool deck through a circular or rectangle lid, about one foot in diameter. If the pool's water pump is operational water is drawn from the pool over a floating hinged weir (operating from a vertical position to 90 degrees angle away from the pool, in order to stop leaves and debris being back-flooded into the pool by wave action), and down into a removable "skimmer basket", the purpose of which is to entrap leaves, dead insects and other larger floating debris. The aperture visible from the pool side is typically 1' 0" (300 mm) wide by 6" (150 mm) high, which intersects the water midway though the center of the aperture. Skimmers with apertures wider than this are termed "wide angle" skimmers and may be as much as 2' 0" wide (600 mm). Floating skimmers have the advantage of not being affected by the level of the water as these are adjusted to work with the rate of pump suction and will retain optimum skimming regardless of water level leading to a markedly reduced amount of bio-material in the water. Skimmers should always have a leaf basket or filter between it and the pump to avoid blockages in the pipes leading to the pump and filter. The water returning to the pool from the consecutive dilution system is passed through return jets below the surface of the water. The return jets are designed to impact a turbulent flow as the water enters the pool. This turbulent flow as a force is far less than the mass of the water in the pool and the turbulent flow takes the least pressure route to the surface where surface tension reforms it into a laminar flow on the surface water. As the returned water disturbs the water surface it creates a capillary wave. The capillary wave if the return jets are positioned correctly creates a circular motion within the surface tension of the water allowing the surface water to slowly circulate around the pool walls. Organic waste floating on the surface through this circulation from the capillary wave is slowly drawn passed the mouth of the skimmer where it is pulled in due to the laminar flow and surface tension over the skimmer weir. In a well designed pool this circulation caused by the disturbed returned water aids in removing organic waste from the pools surface to be trapped inside the consecutive dilution system for easy disposal. Many return jets are equipped with a swivel nozzle which if used correctly will further induce a circulation in the depths of the water further cleaning the pool. When the jet nozzles are turned to one direction e.g. both to the right an anti clockwise rotation within the whole depth of pool water will exist. If turned to the left it will create a clockwise movement within the depths of the water. This rotation has the benefit of cleaning the bottom of the pool and slowly moving sunken inorganic debris to the main drain where the debris is removed by the circulation pump basket sieve. In a correctly constructed pool this rotation of the water caused by the return water from the consecutive dilution system will reduce or even remove the need to hoover the bottom of the pool. To gain the maximum rotation force on the main body of water the consecutive dilution system needs to be as clean and unblocked as possible to allow maximum flow pressure from the pump. As the water rotates it also disturbs organic waste in the lower water layers and forces it to the top of the pool water. This rotational force the pool return jets create is the most important part of cleaning the pool water and pushing organic waste across the mouth of the skimmer. With a correctly designed and operated swimming pool this circulation can be seen and after a period of time the circulation will reach even the deep end and impart a low velocity vortex above the main drain due to suction. Correct use of the return jets is the most effective way of removing disinfection bye products caused by decomposing organic waste from the water depths and pulling it into the consecutive dilution system for immediate disposal. Other equipment which may be optioned in the recirculation system include pool water heaters. They can be heat pumps, natural gas or propane gas heaters, electric heaters, wood burning heaters, or Solar hot water panel heaters - increasingly used in the sustainable design of pools. Diversions to electronic oxidation systems, ionization systems, microbe disinfectinon with ultra-violet lamp systems, and "Tri-Chlor Feeders" are other auxiliary systems for Swimming pool sanitation; as well as solar panels; are in most cases required to be placed after the filtration equipment, and are the last items before the water is returned to the pool. Features that are part of the water circulation system can extend treatment capacity needs for sizing calculations and can include: artificial streams and waterfalls, in-pool fountains, integrated hot tubs and spas, water slides and sluices, artificial "pebble beaches", submerged seating as bench-ledges or as "stools" at in-pool bars, plunge pools, and shallow children's wading pools.
Swimming Pool Design In Nemo