WO2013090873A1 - A composition and method for reducing cyanuric acid in recreational water - Google Patents

Abstract

A composition and method for reducing cyanuric acid in recreational water such as outdoor swimming pools, and more specifically, a composition and method that uses at least of a purine or a pyrimidine to reduce free levels of cyanuric acid in recreational water. A method that use at least one of a purine or a pyrimidine to reduce free levels of cyanuric acid in recreational water as well as a reducing agent or oxidizing agent to prevent the formation of chromophores in the recreation water and yet more specifically to a composition including chlorine, at least one of a purine or a pyrimidine, and a reducing agent or oxidizing agent configured to treat recreational water.

Description

A COMPOSITION AND METHOD FOR REDUCING CYANURIC ACID IN RECREATIONAL WATER

CROSS REFERENCE TO RELATED APPLICATION

[0001] This PCT Patent Application claims the benefit of U.S. provisional application serial number 61/576,417 filed December 16, 2011, the entire disclosure of the application being considered part of the disclosure of this application, and hereby incorporated by reference.

BACKGROUND OF THE INVENTION

[0002] 1. Technical Field

[0003] The present invention is directed to a composition and method for reducing cyanuric acid in recreational water such as outdoor swimming pools, and more specifically, a composition and method that use at least one of a purine or a pyrimidine to reduce free levels of cyanuric acid in recreational water.

[0004] 2. Related Art

[0005] Recreational water, such as swimming pools, water parks, water slides, fountains and many other man-made retained water sources require methods to sanitize and limit the spread of bacteria and disease. Where multiple humans interact with the water, especially with public recreational water, it is important to treat the water to prevent the spread of bacteria and other organisms as well as the illnesses that go therewith. It is also desirable to generally enhance the clarity and visual aspect of the water through the removal of various organisms. To fulfill the above desires, chlorine has been commonly used due to its effectiveness and generally low cost, as compared to other sanitizing chemicals, to ensure the safety of the water quality for the users of the recreational water.

[0006] While chlorine is a very effective and cost-efficient sanitizing chemical, it does have one significant drawback when used outdoors or with filtration systems that include UV sanitizers. Chlorine is known to be susceptible to UV rays and UV exposure may eliminate or significantly reduce the amounts of chlorine available for sanitization purposes. In fact, as little as two hours of UV exposure may significantly reduce the amounts of available chlorine and some pools have been found to lose up to 90% of their available chlorine in a single day due to the UV rays in sunlight.

[0007] Originally to maintain sufficient levels of chlorine, the amount of chlorine in the recreational water, particularly for heavily used public outdoor swimming pools, needed to be monitored every couple of hours to ensure a balance of having enough chlorine to properly sanitize the pool and not too much chlorine. Too little chlorine reduces the effectiveness in sanitizing the water while too much can cause discomfort in the users of the recreational waters such as burning eyes, distasteful smell and even discoloration of some users' hair. However, many times, the person maintaining the recreational water, either in a desire to overcompensate or due to poor training, would add too much chlorine, or in other instances, not realize that the level of chlorine had been reduced by UV rays to a level less than that necessary to provide sanitized water. Also, many states have requirements for minimal chlorine levels in public recreational water to ensure the effectiveness of the chlorine in killing the bacteria or organisms that cause illness in humans. Therefore, the quick degradation of chlorine under UV light made maintaining the proper levels in recreational water time-consuming, difficult, and required frequent additions of chlorine which caused high chemical expenses.

[0008] To combat the degradation of chlorine in response to UV light, some manufacturers add cyanuric acid to their chlorine treatment chemicals for outdoor pools. Some of these combined products include a combination of cyanuric acid and chlorine and are known in the industry as trichlor or dichlor. The cyanuric acid acts as a chlorine stabilizer by forming a weak bond with free chlorine in the water to protect the chlorine from the sun's ultraviolet rays. More specifically, the cyanuric acid reduces chlorine loss in response to UV ray exposure. Therefore, properly managed levels of cyanuric acid reduces the amount of chlorine needed to maintain the minimum chlorine in outdoor recreational water and in many instances, significantly reduces the cost of chemical disinfection by reducing the amount of chlorine that needs to be regularly added.

[0009] Dichlor and trichlor are chlorinated isocyanurates which are two solid chlorine compounds that contain both the chlorine and cyanuric acid so that it is not necessary to add cyanuric acid separately to the recreational water. While the cyanuric acid does reduce the effect of the sun's ultraviolet rays on the free chlorine in the water, over time, because the cyanuric acid is not 100% effective, the chlorine is still lost and needs to be replaced. Therefore, like previously chlorine treatments, chlorine needs to be regularly added to the recreational water, but in significantly reduced quantities than required without the use of cyanuric acid.

[00010] While the chlorine still degrades over time and is reduced in the water due to ultraviolet light exposure, the cyanuric acid is not reduced and remains in the water.

Therefore, since many recreational water operators, such as operators of public swimming pools, continually use the same chemical formulation, the continued use of chlorine in combination with cyanuric acid over time causes the levels of cyanuric acid in the pool to increase. While up to certain levels of cyanuric acid in the recreational water is beneficial, above those levels the cyanuric acid may have negative effects on the sanitizing ability of the chlorine and in view of this problem, some states now regulate the maximum level of cyanuric acid allowed in recreational water.

[00011] Cyanuric acid forms temporary bonds with the free chlorine in the water which generally reduces the amount of available chlorine for sanitization and therefore, the overall effectiveness of the chlorine. Therefore, the amount of time to kill bacteria and other organisms in the water is lengthened as the concentration of cyanuric acid increases and the amount of free chlorine decreases. Therefore, the amount of cyanuric acid in the water must be carefully balanced to both protect the chlorine from rapid degradation under UV light as well as minimize the effect of the cyanuric acid on the overall effectiveness of the chlorine acting as a disinfectant or sanitization chemical. Many states and

municipalities now require that in addition to testing to ensure sufficient chlorine, testing of a pool or other recreational water to ensure that the levels of cyanuric acid are under the stated maximum. Because the cyanuric acid builds up in the water and causes an over- stabilization condition of the chlorine by limiting the amounts of free chlorine as described above, the extended use of stabilized sanitizers especially in conjunction with stabilized shock treatments may create too high of levels of cyanuric acid in the water.

[00012] High levels of cyanuric acid not only decrease the effectiveness of the chlorine in killing bacteria, algae and other organisms but also reduce the oxidation reduction potential or the oxidizing power of the chlorine. Therefore, low levels of cyanuric acid serve a purpose in protecting chlorine from sunlight degradation; however, too much cyanuric acid negates any benefit and causes problems with the effectiveness of the sanitization as well by removing too much free chlorine from the water. In addition, cyanuric acid has also been found to have negative effects on many masonry or plaster pools, including degradation of the pool walls itself as the levels build. In certain tests of pools containing cyanuric acid, when the cyanuric acid level was high, such as above 200 parts/million, surface reaction with the pool structure was observed through the degradation of plaster.

[00013] Because cyanuric acid remains in the pool water and does not generally evaporate or react with any current known chemical that is safe for use in contact with humans, there is no current method for safely removing cyanuric acid from recreational water such as in swimming pools. The only known method of removing cyanuric acid levels in recreational water is to drain a determined amount of water and then refill or replace the amount of water that has been drained. For most pool operators, the calculation of how much water to drain to reduce the cyanuric acid level to an acceptable level, as well as the calculation of the amount of new chemicals to be added once the water is replaced is a very difficult and time-consuming.

[00014] In particular for recreational water used in higher temperature climates, the evaporation of water requires constant adding of water and the subsequent retreatment of the newly added water which is very expensive. This constant treating of newly added water with stabilized chemicals containing cyanuric acid allows the cyanuric acid in a short time to build past acceptable or maximum allowed levels. In fact, to prevent reduced effectiveness of the chlorine, many states and municipalities have mandated that the cyanuric acid be below 100 parts/million, in others now below 80 and in some now even lower. Therefore, recreational water experiencing a high evaporation rate combined with the use of stabilized chemicals having cyanuric acid in combination with chlorine allow levels of cyanuric acid that build up quickly in the recreational water, specifically in swimming pools, and therefore the recreational water must be regularly drained, replaced, and then retreated. Not only are the chemicals expensive but the new water used to dilute the existing water after a significant portion has been drained is typically expensive and therefore, having no mechanism to reduce the cyanuric acid besides drain, refill and retreat is very costly.

[00015] Therefore, there is a need for a method and composition to reduce cyanuric acid within recreational water that is safe when interacting with humans. It is known in the prior art that melamine will form limited bonds or reactions with cyanuric acid. However, melamine is not a chemical that is generally safe to add to recreational water as the ingestion by humans and other animals of melamine could have adverse health effects such as in the kidneys. Melamine combines with cyanuric acid to form a melamine cyanurate which forms large, round, yellow crystals which block and damage renal cells causing kidneys to malfunction. In addition, melamine has an adverse visual effect in that melamine causes the water to have a yellowish tinge through the formation of large yellow crystals and many times the water has a cloudy appearance after the melamine is added to reduce cyanuric acid. Therefore, currently there is no safe and effective method for reducing cyanuric acid in pool water other than draining and refilling with new water.

SUMMARY OF THE INVENTION

[00016] The present invention is directed to a composition and method for reducing cyanuric acid in recreational water such as outdoor swimming pools, and more specifically, a composition and method that use at least one of a purine or a pyrimidine to reduce free levels of cyanuric acid in recreational water and yet more specifically a composition and method that use at least one of a purine or a pyrimidine to reduce free levels of cyanuric acid in recreational water as well as a reducing agent or oxidizing agent to prevent the formation of chromophores in the recreation water and yet more specifically to a composition including chlorine, at least one of a purine or a pyrimidine, and a reducing agent or oxidizing agent configured to treat recreational water.

[00017] The method of the present invention is directed to a method for treating recreational water including cyanuric acid, said method comprising the steps of introducing at least one of a purine and a pyrimidine into the water for reducing the level of cyanuric acid in the recreational water. The method may further include the steps of measuring the cyanuric acid in the recreational water, and determining the amount of cyanuric acid to be removed from the water, before the step of introducing at least one of a purine and a pyrimidine. [00018] The method further includes the step of comparing the measured cyanuric acid, in the step of measuring the cyanuric acid in the recreational water, with a desirable level of cyanuric acid in the recreational water. The step of determining the cyanuric acid in the pool may further include the step of subtracting the desirable level of cyanuric acid from the measured level of cyanuric acid. In turn, the step of subtracting the desirable level further includes the step of determining no action needs to be taken when the step of subtracting yields a number less than or equal to zero.

[00019] The step of determining the amount of cyanuric acid to be removed further includes the step of determining the reduction ratio for the selected at least one of a purine and a pyrimidine. The method may also include the step of measuring the amount of cyanuric acid in the water after a specified time has elapsed since introducing at least one of a purine and pyrimidine. .Additional amounts of the at least one of a purine and a pyrimidine may be added into the water for reducing the cyanuric acid in response to determining that too much cyanuric acid remains in the water after the step of measuring the amount of cyanuric acid in the water after a specified time has elapsed since introducing at least one of a purine and pyrimidine.

[00020] Of course the method can use at least one purine and at least one pyrimidine.

The purine may be selected from the group of purines including adenine, guanine, hypoxanthine, xanthine, theobromine, caffeine, uric acid, isoguanine, 2-amino-6- iodopurine, 2-thioxanthine, 2,8-dimercapto-6-hydroxy purine, 6-mercaptopurine, 6- thioguanine, 2-amino-6-hydroxy-8-mercaptopurine, adenine hydrochloride, guanine hydrochloride, 2,6-diaminopurine, 3-methylpurine, 3-methylxanthine, 6,8-dihydroxy-2- (methylthio) purine and 6-methylthioxanthine. Preferably the purine is selected from the group of purines including hypoxanthine, xanthine, isoguanine, 2-amino-6-iodopurine, 2- thioxanthine, 6-mercaptopurine, 6-thioguanine, 2-amino-6-hydroxy-8-mercaptopurine, adenine hydrochloride, guanine hydrochloride, 2,6-diaminopurine, 3-methylpurine, 3- methylxanthine, and 6-methylthioxanthine. Even more preferably the purine is selected from the group of purines including hypoxanthine, xanthine, 2-amino-6-iodopurine, 2- thioxanthine, 6-thioguanine, , adenine hydrochloride, guanine hydrochloride, 2,6- diaminopurine, and 6-methylthioxanthine.

[00021] If the at least one purine and pyrimidine is a pyrimidine, the pyrimidine may be selected from the group of pyrimidine including cytosine, thymine, uracil, barbituric acid, 4,6-dihydroxy-2-mercapto pyrimidine, orotic acid, 2-chloro-4-methyl pyrimidine, alloxan, 5,6-dihydro-5-methyl uracil, 5,6-dihydrouracil, 5-nitrobarbituric acid, 5-iodouracil, 2-amino-5-iodopyrimidine, pyrimidine, 2-thiouracil, 2,4,5-trihydroxy pyrimidine, 2- mercaptopyrimidine, 2-amino-5-nitropyrimidine, 2-aminopyrimidine, 4-aminopyrimidine, 2-amino-6-hydroxy-2-mercaptopyrimidine, 5-aminouracil, 6-aminouracil, 2,4-diamino-6- hydroxy-5-nitrosopyrimidine, 2,4-diamino-6-hydroxypryimidine, 2,4,6-triaminopyrimidine,

4- hydroxy-2-(trifluoromethyl) pyrimidine, 5-(chloromethyl)uracil, 2-amino-4-chloro-6- methylpyrimidine, 5-hydroxymethyluracil, 4,6-dihydroxy-2-methylpyrimidine, and 6- amino-l-methylnitrouracil. Preferably the pyrimidine is selected from the group of pyrimidine including cytosine, thymine, uracil, barbituric acid, orotic acid, 2-chloro-4- methyl pyrimidine, alloxan, 5,6-dihydrouracil, 5-nitrobarbituric acid, 2-amino-5- iodopyrimidine, pyrimidine, 2-thiouracil, 2,4,5-trihydroxy pyrimidine, 2-amino-5- nitropyrimidine, 2-aminopyrimidine, 4-aminopyrimidine, 6-aminouracil, 2,4-diamino-6- hydroxy-5-nitrosopyrimidine, 2,4-diamino-6-hydroxypryimidine, 2,4,6-triaminopyrimidine,

5- (chloromethyl)uracil, 2-amino-4-chloro-6-methylpyrimidine, 5-hydroxymethyluracil, 4,6- dihydroxy-2-methylpyrimidine, and 6-amino-l-methylnitrouracil. Even more preferably, the pyrimidine is selected from the group of pyrimidine including cytosine, thymine, uracil, barbituric acid, orotic acid, alloxan, 5,6-dihydrouracil, 5-nitrobarbituric acid, 2-thiouracil, 2,4,5-trihydroxy pyrimidine, 2-amino-5-nitropyrimidine, 2-aminopyrimidine, 4- aminopyrimidine, 6-aminouracil, 2,4-diamino-6-hydroxypryimidine, 2,4,6- triaminopyrimidine, 2-amino-4-chloro-6-methylpyrimidine, 5-hydroxymethyluracil, 4,6- dihydroxy-2-methylpyrimidine, and 6-amino-l-methylnitrouracil.

[00022] The method further includes the step of introducing a reducing agent or oxidizing agent into the water. The step of introducing the reducing agents further includes the step of providing a reducing agent selected from the group consisting essentially of lithium aluminum hydride, sodium borohydride, diisobutyl aluminum hydride, sodium hydride, sodium borohydride, calcium hydride, trimethyl borate, sodium thiosulfate, hydrazine, dithiothreitol, aluminum borohydride, aluminum hydride, lithium borohydride, hydrazine, dithionite, hydroxylamine, sodium naphthalenide, hydrogen iodide, oxalic acid, formic acid, various salts of lithium, potassium, barium, magnesium, aluminum, magnesium, zinc (III), tin (II), iron (II), calcium, sodium phosphite, sodium biphosphite, sodium nitrite, sodium sulfite, sodium bisulfite, ascorbic acid, sorbic acid, fumaric acid, L- cysteine, phosphorous acid, and samarium iodide.

[00023] The step of introducing a reducing agent or oxidizing agent into the water includes the step of introducing the reducing agent or oxidizing agent in proportion to a total amount of purine and pyrimidine introduced into the water during the step of introducing at least one of a purine and a pyrimidine into the water for reducing the level of cyanuric acid in the recreational water.

[00024] The present invention is also directed to a method of treating recreation water including cyanuric acid, said method comprising the steps of introducing a chemical composition primarily formed from a heterocyclicorganic compound wherein the ring of said heterocyclic compound includes two nitrogens and four carbons to the recreational water. [00025] The method may also include the steps of measuring the cyanuric acid present in the recreational water to determine the amount of cyanuric acid to be removed from the water, before introducing the chemical composition. The method can include the step of introducing a reducing agent or oxidizing agent into the water.

[00026] The present invention is also directed to a method of stabilizing cyanuric acid in recreational water comprising the steps of introducing at least one of a purine and pyrimidine to the recreational water and introducing a reducing agent and/or oxidizing agent into the recreation water in equal to eighty percent or greater than the total amount of purine and pyrimidine adding during the step of introducing at least one of a purine and pyrimidine to the recreational water. The method includes the step of introducing a reducing agent or oxidizing agent further includes the step of providing a reducing agent selected from the group consisting of lithium aluminum hydride, sodium borohydride, diisobutyl aluminum hydride, sodium hydride, sodium borohydride, calcium hydride, trimethyl borate, sodium thiosulfate, hydrazine, dithiothreitol, aluminum borohydride, aluminum hydride, lithium borohydride, hydrazine, dithionite, hydroxylamine, sodium naphthalenide, hydrogen iodide, oxalic acid, formic acid, various salts of lithium, potassium, barium, magnesium, aluminum, magnesium, zinc (III), tin (II), iron (II), calcium, sodium phosphite, sodium biphosphite, sodium nitrite, sodium sulfite, sodium bisulfite, ascorbic acid, sorbic acid, fumaric acid, L- cysteine, phosphorous acid, and samarium iodide.

[00027] The method further includes the steps of introducing at least one of a purine and pyrimidine to the recreational water and introducing a reducing agent or oxidizing agent into the recreation water in equal to eighty percent or greater than the total amount of purine and pyrimidine adding during the step of introducing at least one of a purine and pyrimidine to the recreational water are performed simultaneously. The method further includes the step of complexing the at least one purine and pyrimidine with the cyanuric acid. [00028] The present invention is also directed to a method of reducing and then stabilizing cyanuric acid in recreational water comprising the steps of introducing a first compound including at least one of a purine and a pyrimidine into the recreational water for reducing the cyanuric acid in the recreational water, introducing a second compound including at least one of a purine and a pyrimidine into the recreational water for stabilizing the cyanuric acid in the recreational water, and introducing a reducing agent or oxidizing agent into the recreational water.

[00029] The present invention is directed to a method of reducing cyanuric acid in recreational water comprising the steps of measuring the cyanuric acid present in the water, comparing the measured cyanuric acid to an ideal operating level of cyanuric acid to determine a desired amount of cyanuric acid to be removed from the recreational water, determining an effective amount of at least one of a purine and pyrimidine to effectively reduce/remove the cyanuric acid and establish the ideal operating level of cyanuric acid, and introducing an effective amount of purine and pyrimidine from the at least one purine and pyrimidine. The method further includes the steps of measuring the cyanuric acid present in the recreational water after a specified time to determine a modified level of cyanuric acid, comparing the modified level of cyanuric acid to the ideal level of cyanuric acid to determine if too much cyanuric acid is still present in the recreational water, calculate an updated effective amount to reduce the level of cyanuric acid in the recreational water, and introducing the calculated updated effective amount of purine and pyrimidine in response to determining too much cyanuric acid is present in the recreational water.

[00030] The present invention is also directed to a product for reducing cyanuric acid in recreational water including at least one of a purine and pyrimidine, and a reducing agent or oxidizing agent. The product may further include chlorine. The reducing agent is selected from the group including lithium aluminum hydride, sodium borohydride, diisobutyl aluminum hydride, sodium hydride, sodium borohydride, calcium hydride, trimethyl borate, sodium thiosulfate, hydrazine, dithiothreitol, aluminum borohydride, aluminum hydride, lithium borohydride, hydrazine, dithionite, hydroxylamine, sodium naphthalenide, hydrogen iodide, oxalic acid, formic acid, various salts of lithium, potassium, barium, magnesium, aluminum, magnesium, zinc (III), tin (II), iron (II), calcium, sodium phosphite, sodium biphosphite, sodium nitrite, sodium sulfite, sodium bisulfite, ascorbic acid, sorbic acid, fumaric acid, L-cysteine, phosphorous acid, and samarium iodide. More preferably the reducing agent is selected from the group consisting of hydrogen iodide, oxalic acid, formic acid, various salts of lithium, potassium, barium, magnesium, aluminum, magnesium, zinc (III), tin (II), iron (II), calcium, sodium phosphite, sodium biphosphite, sodium nitrite, sodium sulfite, sodium bisulfite, ascorbic acid, sorbic acid, fumaric acid, L-cysteine, phosphorous acid, and samarium iodide. The reducing agent is even more preferably selected from the group consisting of sodium phosphite, sodium biphosphite, sodium nitrite, sodium sulfite, sodium bisulfite, ascorbic acid, sorbic acid, fumaric acid, L-cysteine, phosphorous acid, and samarium iodide. Of course, the product must be a composition that is safe for human contact when dissolved in recreational water. In the product, the molar ratio of reducing agent to the total of the at least one of a purine and pyrimidine is expected to be a minimum of 1 to 2 and preferably equal to or greater than 1 to 1.

[00031] While the product may use any of the above described purines and pyrimidines, the product preferably includes at least one of a purine and pyrimidine selected from the group consisting of cytosine, thymine, uracil, barbituric acid, orotic acid, alloxan, 5,6-dihydrouracil, 5-nitrobarbituric acid, 2-thiouracil, 2,4,5-trihydroxy pyrimidine, 2- amino-5-nitropyrimidine, 2-aminopyrimidine, 4-aminopyrimidine, 6-aminouracil, 2,4- diamino-6-hydroxypryimidine, 2,4,6-triaminopyrimidine, 2-amino-4-chloro-6- methylpyrimidine, 5-hydroxymethyluracil, 4,6-dihydroxy-2-methylpyrimidine, 6-amino-l- methylnitrouracil, hypoxanthine, xanthine, 2-amino-6-iodopurine, 2-thioxanthine, 2 6- thioguanine, , adenine hydrochloride, guanine hydrochloride, 2,6-diaminopurine, and 6- methylthioxanthine.

[00032] The present invention is also directed to a product for reducing cyanuric acid in recreational water comprising at least one of a purine and pyrimidine, chlorine, and a reducing agent or oxidizing agent selected from the group consisting of lithium aluminum hydride, sodium borohydride, diisobutyl aluminum hydride, sodium hydride, sodium borohydride, calcium hydride, trimethyl borate, sodium thiosulfate, hydrazine,

dithiothreitol, aluminum borohydride, aluminum hydride, lithium borohydride, hydrazine, dithionite, hydroxylamine, sodium naphthalenide, hydrogen iodide, oxalic acid, formic acid, various salts of lithium, potassium, barium, magnesium, aluminum, magnesium, zinc (III), tin (II), iron (II), calcium, sodium phosphite, sodium biphosphite, sodium nitrite, sodium sulfite, sodium bisulfite, ascorbic acid, sorbic acid, fumaric acid, L-cysteine, phosphorous acid, samarium iodide, hydrogen peroxide, sodium peroxide, sodium peroxydisulfate, sodium peroxy monopersulfate, sodium percarbonate, sodium perborate, sodium

hypochlorite, sodium nitrite, potassium perchlorate, potassium peroxide, hypochlourous acid, potassium peroxide, sodium chlorate, sodium and chlorite.

[00033] In the above product, the at least one at least one of a purine and pyrimidine is selected from the group consisting of hypoxanthine, xanthine, 2-amino-6-iodopurine, adenine hydrochloride, guanine hydrochloride, 2,6-diaminopurine, 6-methylthioxanthine, cytosine, thymine, uracil, barbituric acid, orotic acid, alloxan, 5,6-dihydrouracil, 5- nitrobarbituric acid, 2-thiouracil, 2,4,5-trihydroxy pyrimidine, 2-amino-5-nitropyrimidine, 2-aminopyrimidine, 4-aminopyrimidine, 6-aminouracil, 2,4-diamino-6-hydroxypryimidine, 2,4,6-triaminopyrimidine, 5-hydroxymethyluracil, 4,6-dihydroxy-2-methylpyrimidine, and 6-amino- 1 -methylnitrouracil.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[00034] The present invention is directed to a composition including at least one of a purine and a pyrimidine and a method of using at least one of a purine and a pyrimidine to reduce cyanuric acid in recreational water. As used herein, the term recreational water means any water retained in a created structure where it is desirable to sanitize or disinfect the water to prevent growth of bacteria and other organisms and wherein chlorine is added to the water as the disinfectant or sanitization chemical. Recreational water further as used herein does not include natural features such as lakes, rivers, streams, and any other body of water where chlorine is not intentionally added or desirable to be added. Recreational water as used herein specifically excludes drinking water. Examples of structures that retain recreational water include swimming pools, water parks, water slides, and fountains but do not include water features where it is desirable to have fish or amphibians such as a Koi pond.

[00035] As stated in the Background to the Invention, the prior art specifically teaches that there is no method for reducing cyanuric acid with chemicals safe for human contact, leaving the only option of removal of at least a portion of the water and then filling or replacement of water that does not include cyanuric acid. For example, if a swimming pool is restricted to a maximum level of cyanuric acid of 50 parts/ million and the water in the swimming pool has reached a point of at least 100 parts/million, more than half of the pool water will need to be drained and then replaced to bring the pool under the maximum levels allowed of cyanuric acid.

[00036] Increasingly, states have started to regulate the amounts of cyanuric acid in recreational waters because when the cyanuric acid reaches certain levels, it reduces the effectiveness of the chlorine acting as a sanitizing or disinfectant agent. While the recommended range for cyanuric acid varies depending on the source, most sources state that the ideal range of cyanuric acid is between 30 and 80 parts/million. Other sources state that 40 parts/million is ideal and that level high enough to prevent the sun from destroying the chlorine's effectiveness while yet leaving enough chlorine free to effectively sanitize the pool water. Many states set the maximum level allowed in swimming pools for cyanuric acid at a 100 parts/ million while a few other states or municipalities regulate the cyanuric acid to a maximum level of 80 parts/ million. Recently, Florida has proposed reducing the maximum level of cyanuric acid allowed in swimming pools from 100 parts/million to 40 parts/million. These regulatory decreases in the amount of maximum allowed cyanuric acid make it harder to control the level of cyanuric acid in the recreational water over time, particularly for pools that are not seasonally drained. Previously, because the level of cyanuric acid generally increases gradually, many swimming pools that were closed and at least partially drained in the winter could make it through the open season without needing to reduce the level of cyanuric acid while other swimming pools open all year only needed to reduce the level through dilution by removing water and replacing it once or twice a year. In view of the new regulatory lower levels of maximum allowed cyanuric acid, the required reductions in cyanuric acid are occurring with increasing frequency.

[00037] The inventors have unexpectedly found that contrary to the statements in the prior art, that there is no chemical method for safely reducing cyanuric acid, that some purines and pyrimidines successfully, effectively, and safely reduce cyanuric acid. In addition, some purines and pyrimidines are extremely effective and fast acting while others are less effective immediately but are slower acting which allows the development of compositions that provided immediate reductions in the cyanuric acid as well as long term stabilization of cyanuric acid levels in the recreational water. [00038] While most of the purines and pyrimidines discovered by the inventors are effective at reducing cyanuric acid, some of them create white solids that are then dispersed in the recreational water giving a cloudy or milky appearance to the water. For some uses, the lack of clarity may be acceptable in recreational water and therefore these purines and pyrimidines may be used but for swimming pools and similar types of recreational water, where the clarity of the water is very desirable, these purines and pyrimidines that create cloudy water through suspended solids are not expected to be used. Applicants have found a variety of purines and pyrimidines that although when they react with the cyanuric acid to create fine white solids, the overall recreational water is still substantially clear and has the desired clarity and visual appearance for swimming pools. For example, one pyrimidine that works exceptionally well with a reduction of almost 1: 1, is fast-acting and provides the desired visual clarity is barbituric acid. In comparison, 6-amino-l-methyl-5-nitrosouracil is a pyrimidine that has a reduction of about one cyanuric acid for every two of the pyrimidine but creates a pink solid when it reacts with cyanuric acid and therefore leaves the recreational water a slight pink color. Certain other purines and pyrimidines can create other colors such as green and orange which in limited circumstances also allow at times for tinting of the water. These solids or other chemical interactions create chromophores that may tinge the color of the water. These chromophores may not be visible in a laboratory, but are visible in the quantities of water typical in a swimming pool. The present invention uses various reducing agents or oxidizing agents as described in detail below to minimize the effect of chromophores.

[00039] A pyrimidine is a heterocyclic aromatic organic compound containing two nitrogen atoms at position 1 and 3 of the six member ring. The other atoms of the ring are formed from carbon. Many pyrimidines do photolytically decompose into uracil under UV light which is a pyrimidine derivative and is common and naturally occurring. Uracil is one of the four nucleobasis in the nucleaic acid of RNA that are represented by the letters AGC and U typically. Because the pyrimidines can decompose in UV light to uracil, even if the operator of the recreational water adds too much, over time and therefore after combining with and reducing the cyanuric acid, the remaining pyrimidines naturally reduce which allows the remaining desirable cyanuric acid necessary to protect the chlorine from being destroyed by UV light to perform its task. Therefore, the use of pyrimidines allows for easy methods of reducing cyanuric acid and errors of adding too much pyrimidine have little long term effects.

[00040] Purine is a heterocyclic aromatic organic compound consisting of a pyrimidine ring fused to an imidazole ring. Purines including substituted purines and their tautomers are the most widely distributed nitrogen containing heterocyclic in nature.

Therefore, generally speaking as with pyrimidines, purines would have little to no side effects when included in the recreational water on humans and animals, unlike melamine which is a triazine. Purines and pyrimidines make up two groups of the nitrogenous bases including two groups of nucleotide bases. The quantity of natural occurring purines produced on Earth is huge with about half of the bases in nucleic acids, adenine, and guanine. In DNA these bases form hydrogen bonds with their complementary pyrimidines, thymine, and cytosine respectfully. Other notable purines are hypoxanthine, xanthine, theobromine, caffeine, uric acid, and isoguanine. The below list of purines and pyrimidines has not been tested by the inventors unless otherwise noted here or otherwise in this application as effective at reducing cyanuric acid. A list of examples of purines and pyrimidines that Applicants have tested that successfully worked is provided below.

[00041] The present invention includes a composition, which is a combination of chlorine and at least one of a purine and pyrimidine for use in treatment for recreational water and a binder. The chlorine forms substantially a majority of the composition and the at least one of a purine or a pyrimidine forms up to 40%. Of course, the composition can include both of a purine and a pyrimidine as well as a combination of purines or pyrimidines. In some instances, a plurality of purines and pyrimidines is desirable to provide an immediate reduction in cyanuric acid similar to a shock treatment for a pool and then additionally provide long term stabilization of the cyanuric acid such that the cyanuric acid remains present in the recreational water but in a quantity that is under the desired maximum limit. The composition may also be formed solely out of the selected purine and pyrimidine as well as including a filler material or other material or other pool treatment chemical in combination therewith. Of course, in these compositions a plurality of purines and/or pyrimidines may also be used. As described in more detail below, the composition may also include a reducing agent or an oxidizing agent.

[00042] The present invention includes a method of reducing cyanuric acid, which at its most basic step is adding at least one of a purine or pyrimidine to reduce cyanuric acid in recreational water. Of course, before the at least one of a purine or a pyrimidine would be added as a reducer of cyanuric acid to recreational water, the recreational water would need to be tested for the presence of cyanuric acid with a determination of whether or not the cyanuric acid is above the allowable maximum level. Therefore, an exemplary method of the present invention includes the steps of supplying at least one of a purine or pyrimidine for use in reducing cyanuric acid in recreational water, instructing on the use of the supplied at least one purine and pyrimidine for reducing cyanuric acid in recreational water, testing to determine the current level of cyanuric acid in recreational water, determining if the current level of tested cyanuric acid in the recreational water is within a desired range for cyanuric acid and in particular, whether or not the tested level of cyanuric acid level is above any maximum allowable limit for cyanuric acid in recreational water, introducing the supplied at least one purine and pyrimidine in recreational water in a desired quantity sufficient to reduce the tested level of cyanuric acid in the recreational water underneath the maximum allowable limit while leaving enough cyanuric acid in the recreational water to protect chlorine in the recreational water from UV degradation.

[00043] As discussed above, certain purines and pyrimidines have been found to create chromophores. A chromophore generally is the part of a molecule responsible for its color. The color arises when a molecule absorbs certain wavelengths of visible light and transmits or reflects others. The chromophore is a region in the molecule where the energy difference between two different molecular orbitals falls within the range of the visible spectrum. Visible light that hits the chromophore can thus be absorbed by exciting an electron from its ground state into an excited state. In some of the examples, a

chromophore which made the water look green was created, a typically undesirable color for swimming pools. To eliminate the effect of chromophores, a reducing agent or oxidizing agent was used in combination with a purine and/or pyrimidine to complex the cyanuric acid in the water. It is believed that the reducing agent or oxidizing agent ensures that there is not chromophore formation as the reducing agent or oxidizing agent, as described below can control the color and intensity for most purines and pyrimidines to eliminate the color stemming from the chromaphore. It is believed that the reducing agent does this by adding electrons to the molecular inductively formed complex, whereas the oxidizing agent does so through the removal of electrons from the molecular inductively formed complex to eliminate the color and intensity.

[00044] It is believed that when the purine and/or pyrimidine is inductively complexed with the cyanuric acid it forms a chromophore which may be a variety of colors, but usually is green. In the laboratory as well as for some purines and pyrimidines in shallow water, the added color tint to the water from the chromophore is almost

imperceptible, but as the depth of the water increases, the color intensity does as well. Pool owners generally desire crystal clear water and therefore such a color appearance, especially green, is unacceptable.

[00045] To reduce the formation of chromophores and therefore the ability of the water, with the addition of purines and pyrimidines to cause a color tint, the present invention balances maintaining the cyanuric acid as complexed with the purine and/or pyrimidine, but eliminates or controls the color through the use of a reducing agent. It is believed that the reducing agent or oxidizing agent is pumping electrons into the complexed cyanuric acid molecule and therefore stabilizing it. It is further believed that the reducing agent in interacting with the complexed cyanuric acid molecule changes the reflective nature of the chromophore such that there is no apparent color observed. Any known reducing agent is believed to work, but the choices of reducing agents are limited in that they must be safe for human contact in swimming pools. Therefore, while there are numerous reducing agents that will function acceptably, the most effective are first chosen based upon functionality, no human toxicity and cost. Reducing agents meeting the above qualifications and found to be useful include lithium aluminum hydride, sodium

borohydride, diisobutyl aluminum hydride, sodium hydride, sodium borohydride, calcium hydride, trimethyl borate, sodium thiosulfate, hydrazine, dithiothreitol, aluminum

borohydride, aluminum hydride, lithium borohydride, hydrazine, dithionite, hydroxylamine, sodium naphthalenide, and others. Reducing agents that are preferred include materials such as hydrogen iodide, oxalic acid, formic acid, various salts of lithium, potassium, barium, magnesium, aluminum, magnesium, zinc (III), tin (II), iron (II), calcium, and the like. Reducing agents that are most preferred are sodium phosphite, sodium biphosphite, sodium nitrite, sodium sulfite, sodium bisulfite, ascorbic acid, sorbic acid, fumaric acid, L- cysteine, phosphorous acid, samarium iodide and the like. Analogously, it is further believed that the oxidizing agent in interacting with the complexed cyanuric acid molecule changes the reflective nature of the chromaphore such that there is no apparent color observed. Any known oxidizing agent is believe to work, but the choices of oxidizing agents are limited in that they must be safe for human contact in swimming pools.

Therefore, while there are numerous oxidizing agents that will function acceptably, the most effective are the first chosen based upon functionality, no human toxicity and cost.

Oxidizing agents meeting the above qualifications and found to be useful include, hydrogen peroxide, sodium peroxide, sodium peroxydisulfate, sodium peroxy monopersulfate, sodium percarbonate, sodium perborate, sodium hypochlorite, sodium nitrite, potassium

perchlorate, potassium peroxide, hypochlourous acid, potassium peroxide, sodium chlorate, sodium, chlorite, and the like.

[00046] As discussed above, the amount of purine and/or pyrimidine is dependent upon the level to which it is desired to drop the amount of cyanuric acid. If the amount of cyanuric acid measured in the volume of water is 80 ppm and it is desired to decrease the level to 50 ppm, then 30 ppm of the purine and/or pyrimidine is required to remove that amount of cyanuric acid through inductive complexing for the exemplary purines and/or pyrimidines that reduce in a one to one ratio. For other than a one to one ratio of reduction, the amount of purine and/or pyrimidine added would be adjusted. To prevent the formation of a chromophore, if 30 ppm of a purine and/or a pyrimidine is added, then preferably approximately 60 parts of a reducing agent or oxidizing agent is also added. More specifically the amount of reducing agent or oxidizing agent added is in equal or greater than part proportion to the purine and/or pyrimidine. Effective ranges have been found to be approximately equal to or greater than one to one reducing agent or oxidizing agent to purine and/or pyrimidine. While the reducing agent or oxidizing agent may be added in sufficient quantities above a one to one ratio with the purines and/or pyrimidines, there is little need to add additional reducing or oxidizing agent so that the ratio in the pool water is two to one. Any additional reducing or oxidizing agent only increases the amount of chemicals in the swimming pool water and also increases the cost of the chemicals.

[00047] In the treatment of pool water, it is a matter of convention to make all calculations based upon 1000 gallons. For instance if a pound of anything is added, that would be 120 mg/L or 120 ppm. From this point it is simple to calculate how much of anything to add by knowing the ppm level to be reached and the volume of the body of water being treated. For instance, a 5000 gallon pool has 100 ppm of cyanuric acid and it is desired to drop this level to 50 ppm. Therefore, 50 ppm of a purine and/or pyrimidine, and 100 ppm of a reducing agent will have to be added. This means that 946 grams or 2.1 pounds of a purine and/or pyrimidine will have to be added , and 1892 grams or 4.2 pounds of a reducing agent will need to be added for each 5000 gallons of water.

[00048] One exemplary composition is a blend of barbituric acid and sodium bisulfate at a 1:2 ratio by weight. The composition may further include additional purines and pyrimidines in combination also with a reducing agent. Additionally chlorine may be added to the composition. An additional exemplary composition is a blend of barbituric acid and sodium percarbonate in a similar ratio of 1:2 ratio by weight. The composition may further include additional purine and/or pyrimidines in combination with the reducing agent or oxidizing agent.

[00049] The following are further examples of test performed in various sized pools.

Example 1

[00050] A 900 gallon pool was filled with fresh water. It was shocked with calcium hypochlorite with an amount such that the final free chlorine was 0.12 ppm. To the pool was then added 409 grams, or 120 ppm, of cyanuric acid. Due to the poor solubility of cyanuric acid, it was pre-dissolved in warm water and then added to the pool. Once the cyanuric acid was uniformly distributed, 205 grams or 60 ppm of barbituric acid was added. The pool turned a light green color and the cyanuric acid level was measured to be 52 ppm, indicating the barbituric acid did inductively complex the cyanuric acid. Next 300 grams or about 90 ppm of sodium bisulfite was added. Within 20 minutes the green color was gone and the cyanuric acid was measured to be 54 ppm. From this test is was clear the barbituric acid was effective in removing cyanuric acid and the sodium bisulfite stabilized the complexed chromophore so that no color was observed.

Example 2

[00051] A 25,000 gallon pool was treated with trichloroisocyanuric acid and was measured to have a free chlorine level of 0.03 ppm and a cyanuric acid level of 104 ppm. The intention was to reduce the amount of cyanuric acid in half. Accordingly 4.9 Kg of 4,6- dihydroxy-2-mercaptopyrimidine were added. After allowing the pool to recirculate for 24 hours, the cyanuric acid level was measure to be 48 ppm. The pool was however a dark green color. 9.8 Kg of sodium nitrite were added and allowed to recirculate for another 24 hours. The green color was gone and a clear pool was observed. The cyanuric acid was measured to be 48 ppm. After two weeks, the pool was still observed to be clear and the cyanuric acid was measured to be 51 ppm.

Example 3

[00052] In like manner as described in Example 1, the pool with fresh water was shocked with calcium hypochlorite to give a free chlorine level of 0.14 ppm. To the pool was added 682 grams, or 200 ppm, of cyanuric acid. The cyanuric acid was similarly pre- dissolved in warm water and added to the pool. After two hours of recirculation, 340 grams of xanthine were added which is 100 ppm. After the cyanuric acid was measured it was reduced further than the theoretical level of 100 ppm to be measured at 27 ppm. The water was however green. To remove the discoloration from the formed chromophore, 340 grams of phosphorous acid were added. Although the discoloration was significantly reduced, there still remained a greenish tint. An additional 170 grams of phosphorous acid were added. After recirculation, the tint appeared to be gone. As a comparative test, another 170 grams of phosphorous acid were added and recirculated. No change was observed indicating that 510 grams or 150 ppm were adequate to remove the green tint.

Example 4

[00053] In like manner as described in Example 1, all elements were repeated exactly except 300 grams of hydrazine were added as the reducing agent. Before the color was removed, and additional 600 grams were required for a total of 270 ppm. From a commercial point of view, hydrazine would not be practical but was tested to show that various reducing agents are effective.

Example 5

[00054] In like manner as described in Example 2, the cyanuric acid level was elevated to 110 ppm by the calculated addition of cyanuric acid. The chlorine source remained as trichloroisocyanurate. And was measured to be 0.05 ppm of free chlorine prior to adding and material to reduce the cyanuric acid. With a stable pool, 5.7 Kg of alloxan (2,4,5, 6-tetraoxypyrimidine) were added and allowed to recirculate for 24 hours. The intent was to reduce the cyanuric acid to 50 ppm. The measured level was 42 ppm indicating alloxan to be effective in complexing with cyanuric acid. The pool was again discolored to a light green color indicating also the formation of a chromophore. 5.7 Kg of L-cysteine were added and allowed to recirculate for 24 hours after which the pool was essentially free of color with just a very light green tint remaining. An additional 1.43 Kg of L-cysteine, for a total of 75 ppm, were added and recirculated for 24 hours. The pool was returned to a fully clear state with no discoloration. After three weeks, the pool was revisited. The water was clear and the cyanuric acid level was measured to be 51 ppm thereby indicating an effective removal of cyanuric acid that remained stable with time under normal outdoor conditions.

Example 6

[00055] In like manner as described in Example 1, the 900 gallon pool was charged with fresh water and shocked with sodium dichloroisocyanurate. To this was added an excessive amount of cyanuric acid. 1227 grams, or 360 ppm of cyanuric acid were added. Using the test method available, the reading was off scale. Through dilution the cyanuric acid was measured to be 349 ppm. The intention was to reduce the cyanuric acid level to 50 ppm. Accordingly, 1.02 Kg of uracil (2-oxy-4-oxy pyrimidine) was added. The cyanuric acid level was dropped to 62 ppm. An additional 50 grams of the uracil were added and allowed to recirculate for three hours. The cyanuric acid was measured to be 51 ppm. The color of the water was again green. 1.07 Kg of sodium biphosphite was added to remove the green tint. After recirculating for three hours, there still remained a green tint. An additional 0.53 Kg of sodium biphosphite was added and allowed to recirculate for three hours. The water was clear and free of discoloration. This required about 450 ppm of reducing agent to remove the discoloration from about 300 ppm of uracil.

[00056] The foregoing discussion discloses and describes an exemplary embodiment of the present invention. One skilled in the art will readily recognize from such discussion, and from the accompanying drawings and claims that various changes, modifications and variations can be made therein without departing from the true spirit and fair scope of the invention as defined by the following claims.

Claims

CLAIMS In The Claims:

Claim 1. A method for treating recreational water including cyanuric acid, said method comprising the steps of:

introducing at least one of a purine and a pyrimidine into the water for reducing the level of cyanuric acid in the recreational water.

Claim 2. The method of Claim 1 further including the steps of:

measuring the cyanuric acid in the recreational water; and

determining the amount of cyanuric acid to be removed from the water, before said step of introducing at least one of a purine and a pyrimidine.

Claim 3. The method of Claim 2 further including the step of comparing the measured cyanuric acid, in said step of measuring the cyanuric acid in the recreational water, with a desirable level of cyanuric acid in the recreational water, with a desirable level of cyanuric acid in the recreational water.

Claim 4. The method of Claim 3 wherein said step of determining the cyanuric acid in the pool further includes the step of subtracting the desirable level of cyanuric acid from the measured level of cyanuric acid.

Claim 5. The method of Claim 4 wherein said step of subtracting the desirable level further includes the step of determining no action needs to be taken when the step of subtracting yields a number less than or equal to zero.

Claim 6. The method of Claim 2 wherein said step of determining the amount of cyanuric acid to be removed includes the step of determining the reduction ratio for the selected at least one of a purine and a pyrimidine.

Claim 7. The method of Claim 2 further including the step of measuring the amount of cyanuric acid in the water after a specified time has elapsed since introducing at least one of a purine and pyrimidine.

Claim 8. The method of Claim 7 further including the step of introducing additional amount of at least one of a purine and a pyrimidine into the water for reducing the cyanuric acid in response to determining that too much cyanuric acid remains in the water after said step of measuring the amount of cyanuric acid in the water after a specified time has elapsed since introducing at least one of a purine and pyrimidine.

Claim 9. The method of Claim 1 wherein said at least one of a purine and a pyrimidine is a purine.

Claim 10. The method of Claim 1 wherein said at least one of a purine and pyrimidine includes at least one purine and at least one pyrimidine.

Claim 11. The method of Claim 9 wherein said purine is selected from the group consisting of purine, adenine, guanine, hypoxanthine, xanthine, theobromine, caffeine, uric acid, isoguanine, 2-amino-6-iodopurine, 2-thioxanthine, 2,8-dimercapto-6- hydroxy purine, 6-mercaptopurine, 6-thioguanine, 2-amino-6-hydroxy-8-mercaptopurine, adenine hydrochloride, guanine hydrochloride, 2,6-diaminopurine, 3-methylpurine, 3- methylxanthine, 6,8-dihydroxy-2-(methylthio) purine and 6-methylthioxanthine..

Claim 12. The method of claim 11 wherein said purine is selected from the group consisting of purine, hypoxanthine, xanthine, isoguanine, 2-amino-6-iodopurine, 2- thioxanthine, 6-mercaptopurine, 6-thioguanine, 2-amino-6-hydroxy-8-mercaptopurine, adenine hydrochloride, guanine hydrochloride, 2,6-diaminopurine, 3-methylpurine, 3- methylxanthine, and 6-methylthioxanthine.

Claim 13. The method of Claim 12 wherein said purine is selected from the group consisting of hypoxanthine, xanthine, 2-amino-6-iodopurine, 2-thioxanthine, 6- thioguanine, adenine hydrochloride, guanine hydrochloride, 2,6-diaminopurine, and 6- methylthioxanthine.

Claim 14. The method of Claim 1 wherein said at least one of a purine and a pyrimidine is a pyrimidine.

Claim 15. The method of Claim 14 wherein said pyrimidine is selected from the group consisting of cytosine, thymine, uracil, barbituric acid, 4,6-dihydroxy-2-mercapto pyrimidine, orotic acid, 2-chloro-4-methyl pyrimidine, alloxan, 5,6-dihydro-5-methyl uracil, 5,6-dihydrouracil, 5-nitrobarbituric acid, 5-iodouracil, 2-amino-5-iodopyrimidine, pyrimidine, 2-thiouracil, 2,4,5-trihydroxy pyrimidine, 2-mercaptopyrimidine, 2-amino-5- nitropyrimidine, 2-aminopyrimidine, 4-aminopyrimidine, 2-amino-6-hydroxy-2- mercaptopyrimidine, 5-aminouracil, 6-aminouracil, 2,4-diamino-6-hydroxy-5- nitrosopyrimidine, 2,4-diamino-6-hydroxypryimidine, 2,4,6-triaminopyrimidine, 4- hydroxy-2-(trifluoromethyl)pyrimidine, 5-(chloromethyl)uracil, 2-amino-4-chloro-6- methylpyrimidine, 5-hydroxymethyluracil, 4,6-dihydroxy-2-methylpyrimidine, and 6- amino- 1 -methylnitrouracil.

Claim 16. The method of claim 15 wherein said pyrimidine is selected from the group consisting of cytosine, thymine, uracil, barbituric acid, orotic acid, 2-chloro-4-methyl pyrimidine, alloxan, 5,6-dihydrouracil, 5-nitrobarbituric acid, 2-amino-5-iodopyrimidine, pyrimidine, 2-thiouracil, 2,4,5-trihydroxy pyrimidine, 2-amino-5-nitropyrimidine, 2- aminopyrimidine, 4-aminopyrimidine, 6-aminouracil, 2,4-diamino-6-hydroxy-5- nitrosopyrimidine, 2,4-diamino-6-hydroxypryimidine, 2,4,6-triaminopyrimidine, 5- (chloromethyl)uracil, 2-amino-4-chloro-6-methylpyrimidine, 5-hydroxymethyluracil, 4,6- dihydroxy-2-methylpyrimidine, and 6-amino-l-methylnitrouracil.

Claim 17. The method of Claim 16 wherein said pyrimidine is selected from the group consisting of cytosine, thymine, uracil, barbituric acid, orotic acid, alloxan, 5,6- dihydrouracil, 5-nitrobarbituric acid, 2-thiouracil, 2,4,5-trihydroxy pyrimidine, 2-amino-5- nitropyrimidine, 2-aminopyrimidine, 4-aminopyrimidine, 6-aminouracil, 2,4-diamino-6- hydroxypryimidine, 2,4,6-triaminopyrimidine, 2-amino-4-chloro-6-methylpyrimidine, 5- hydroxymethyluracil, 4,6-dihydroxy-2-methylpyrimidine, and 6-amino-l-methylnitrouracil.

Claim 18. The method of Claim 1 further including the step of introducing at least one of a reducing agent and an oxidizing agent into the water.

Claim 19. The method of Claim 18 wherein said step of introducing at least one of a reducing agent and an oxidizing agent further includes the step of providing a reducing agent selected from the group consisting essentially of lithium aluminum hydride, sodium borohydride, diisobutyl aluminum hydride, sodium hydride, sodium borohydride, calcium hydride, trimethyl borate, sodium thiosulfate, hydrazine, dithiothreitol, aluminum

borohydride, aluminum hydride, lithium borohydride, hydrazine, dithionite, hydroxylamine, sodium naphthalenide, hydrogen iodide, oxalic acid, formic acid, various salts of lithium, potassium, barium, magnesium, aluminum, magnesium, zinc (III), tin (II), iron (II), calcium, sodium phosphite, sodium biphosphite, sodium nitrite, sodium sulfite, sodium bisulfite, ascorbic acid, sorbic acid, fumaric acid, L-cysteine, phosphorous acid, and samarium iodide.

Claim 20. The method of Claim 18 wherein said step of introducing at least one of a reducing agent and an oxidizing agent further includes the step of providing an oxidizing agent selected from the group consisting essentially of hydrogen peroxide, sodium peroxide, sodium peroxydisulfate, sodium peroxy monopersulfate, sodium percarbonate, sodium perborate, sodium hypochlorite, sodium nitrite, potassium perchlorate, potassium peroxide, hypochlourous acid, potassium peroxide, sodium chlorate, sodium and chlorite.

Claim 21. The method of Claim 1 further including the said step of introducing a reducing agent into the water in proportion to a total amount of purines and pyrimidines introduced into the water during said step of introducing at least one of a purine and a pyrimidine into the water for reducing the level of cyanuric acid in the recreational water.

Claim 22. A method of treating recreation water including cyanuric acid, said method comprising the steps of: introducing a chemical composition primarily formed from a heterocyclicorganic compound wherein the ring of said heterocyclic compound includes two nitrogens and four carbons to the recreational water.

Claim 23. The method of Claim 22 further including the steps of:

measuring the cyanuric acid present in the recreational water to determine the amount of cyanuric acid to be removed from the water, before introducing the chemical composition.

Claim 24. The method of Claim 22 further including the step of introducing a reducing agent into the water.

Claim 25. A method of stabilizing cyanuric acid in recreational water comprising the steps of:

introducing at least one of a purine and pyrimidine to the recreational water; and introducing a reducing agent into the recreation water in equal to eighty percent or greater than the total amount of purine and pyrimidines adding during said step of introducing at least one of a purine and pyrimidine to the recreational water.

Claim 26. The method of Claim 25 wherein said step of introducing a reducing agent further includes the step of providing a reducing agent selected from the group consisting of lithium aluminum hydride, sodium borohydride, diisobutyl aluminum hydride, sodium hydride, sodium borohydride, calcium hydride, trimethyl borate, sodium thiosulfate, hydrazine, dithiothreitol, aluminum borohydride, aluminum hydride, lithium borohydride, hydrazine, dithionite, hydroxylamine, sodium naphthalenide, hydrogen iodide, oxalic acid, formic acid, various salts of lithium, potassium, barium, magnesium, aluminum, magnesium, zinc (III), tin (II), iron (II), calcium, sodium phosphite, sodium biphosphite, sodium nitrite, sodium sulfite, sodium bisulfite, ascorbic acid, sorbic acid, fumaric acid, L- cysteine, phosphorous acid, and samarium iodide.

Claim 27. The method of Claim 25 wherein said steps of introducing at least one of a purine and pyrimidine to the recreational water; and introducing a reducing agent into the recreation water in equal to eighty percent or greater than the total amount of purine and pyrimidines adding during said step of introducing at least one of a purine and pyrimidine to the recreational water are performed simultaneously.

Claim 28. The method of Claim 25 further including the step of complexing the at least one purine and pryrmidine with the cyanuric acid.

Claim 29. A method of reducing and then stabilizing cyanuric acid in recreational water comprising the steps of:

introducing a first compound including at least one of a purine and a pyrimidine into the recreational water for reducing the cyanuric acid in the recreational water;

introducing a second compound including at least one of a purine and a pyrimidine into the recreational water for stabilizing the cyanuric acid in the recreational water; and introducing a reducing agent into the recreational water.

Claim 30. A method of reducing cyanuric acid in recreational water comprising the steps of:

measuring the cyanuric acid present in the water; comparing the measured cyanuric acid to an ideal operating level of cyanuric acid to determine a desired amount of cyanuric acid to be removed from the recreational water; determining an effective amount of at least one of a purine and pyrimidine to effectively reduce/remove the cyanuric acid and establish the ideal operating level of cyanuric acid; and

introducing an effective amount of purine and pyrimidine from the at least one purine and pyrimidine.

Claim 31. The method of Claim 30 further including the steps of:

measuring the cyanuric acid present in the recreational water after a specified time to determine a modified level of cyanuric acid;

comparing the modified level of cyanuric acid to the ideal level of cyanuric acid to determine if too much cyanuric acid is still present in the recreational water;

calculate an updated effective amount to reduce the level of cyanuric acid in the recreational water; and

introducing the calculated updated effective amount of purine and pyrimidine in response to determining too much cyanuric acid is present in the recreational water.

Claim 32. A product for reducing cyanuric acid in recreational water comprising:

at least one of a purine and pyrimidine; and

a reducing agent.

Claim 33. The product of Claim 32 further including chlorine.

Claim 34. The product of Claim 32 wherein said reducing agent is selected from the group consisting of lithium aluminum hydride, sodium borohydride, diisobutyl aluminum hydride, sodium hydride, sodium borohydride, calcium hydride, trimethyl borate, sodium thiosulfate, hydrazine, dithiothreitol, aluminum borohydride, aluminum hydride, lithium borohydride, hydrazine, dithionite, hydroxylamine, sodium naphthalenide, hydrogen iodide, oxalic acid, formic acid, various salts of lithium, potassium, barium, magnesium, aluminum, magnesium, zinc (III), tin (II), iron (II), calcium, sodium phosphite, sodium biphosphite, sodium nitrite, sodium sulfite, sodium bisulfite, ascorbic acid, sorbic acid, fumaric acid, L-cysteine, phosphorous acid, and samarium iodide.

Claim 35. The product of Claim 34 wherein said reducing agent is selected from the group consisting of hydrogen iodide, oxalic acid, formic acid, various salts of lithium, potassium, barium, magnesium, aluminum, magnesium, zinc (III), tin (II), iron (II), calcium, sodium phosphite, sodium biphosphite, sodium nitrite, sodium sulfite, sodium bisulfite, ascorbic acid, sorbic acid, fumaric acid, L-cysteine, phosphorous acid, and samarium iodide.

Claim 36. The product of Claim 35 wherein said reducing agent is selected from the group consisting of sodium phosphite, sodium biphosphite, sodium nitrite, sodium sulfite, sodium bisulfite, ascorbic acid, sorbic acid, fumaric acid, L-cysteine, phosphorous acid, and samarium iodide.

Claim 37. The product of Claim 32 wherein said composition is safe for human contact when dissolved in recreational water.

Claim 38. The product of Claim 32 wherein molar ratio of reducing agent to the total of the at least one of a purine and pyrimidine is a minimum of 1 to 2.

Claim 39. The product of Claim 38 wherein said molar ratio is approximately equal to or greater than 1 to 1.

Claim 40. The product of Claim 32 wherein said at least one at least one of a purine and pyrimidine is selected from the group consisting of cytosine, thymine, uracil, barbituric acid, orotic acid, alloxan, 5,6-dihydrouracil, 5-nitrobarbituric acid, 2-thiouracil, 2,4,5-trihydroxy pyrimidine, 2-amino-5-nitropyrimidine, 2-aminopyrimidine, 4- aminopyrimidine, 6-aminouracil, 2,4-diamino-6-hydroxypryimidine, 2,4,6- triaminopyrimidine, 2-amino-4-chloro-6-methylpyrimidine, 5-hydroxymethyluracil, 4,6- dihydroxy-2-methylpyrimidine, 6-amino-l-methylnitrouracil, hypoxanthine, xanthine, 2- amino-6-iodopurine, 2-thioxanthine, 6-thioguanine, adenine hydrochloride, guanine hydrochloride, 2,6-diaminopurine, and 6-methylthioxanthine.

Claim 41. The product of Claim 32 wherein said at least one of a purine and pyrimidine is barbituric acid and said reducing agent is sodium bisulfate.

Claim 42. The product of Claim 41 wherein said ratio of barbituric acid and socium bisulfate is about 1:2 by weight.

Claim 43. A product for reducing cyanuric acid in recreational water comprising:

at least one of a purine and pyrimidine; chlorine; and

a reducing agent selected from the group consisting of lithium aluminum hydride, sodium borohydride, diisobutyl aluminum hydride, sodium hydride, sodium borohydride, calcium hydride, trimethyl borate, sodium thiosulfate, hydrazine,

dithiothreitol, aluminum borohydride, aluminum hydride, lithium borohydride, hydrazine, dithionite, hydroxylamine, sodium naphthalenide, hydrogen iodide, oxalic acid, formic acid, various salts of lithium, potassium, barium, magnesium, aluminum, magnesium, zinc (III), tin (II), iron (II), calcium, sodium phosphite, sodium biphosphite, sodium nitrite, sodium sulfite, sodium bisulfite, ascorbic acid, sorbic acid, fumaric acid, L-cysteine, phosphorous acid, and samarium iodide.

Claim 44. The product of Claim 43 wherein said at least one at least one of a purine and pyrimidine is selected from the group consisting of hypoxanthine, xanthine, 2- amino-6-iodopurine, adenine hydrochloride, guanine hydrochloride, 2,6-diaminopurine, 6- methylthioxanthine, cytosine, thymine, uracil, barbituric acid, orotic acid, alloxan, 5,6- dihydrouracil, 5-nitrobarbituric acid, 2-thiouracil, 2,4,5-trihydroxy pyrimidine, 2-amino-5- nitropyrimidine, 2-aminopyrimidine, 4-aminopyrimidine, 6-aminouracil, 2,4-diamino-6- hydroxypryimidine, 2,4,6-triaminopyrimidine, 5-hydroxymethyluracil, 4,6-dihydroxy-2- methylpyrimidine, and 6-amino-l-methylnitrouracil.