Patent Publication Number: US-2021179454-A1

Title: Systems and Methods for Sanitizing Pool and Spa Water

Description:
RELATED APPLICATIONS 
     The present application is continuation of U.S. patent application Ser. No. 15/927,412, filed Mar. 21, 2018, which claims priority to U.S. Provisional Application Ser. No. 62/474,333 filed on Mar. 21, 2017, the entire disclosures of both of which are expressly incorporated by reference herein. 
    
    
     BACKGROUND 
     Field of the Disclosure 
     The present disclosure relates generally to the field of pool and spa equipment. More particularly, the present disclosure relates to systems and methods for sanitizing pool and spa water. 
     Related Art 
     Fluid sanitization systems have been provided in the past for sanitizing pool and spa water. For example, assemblies for sanitizing and/or disinfecting water have been developed. Fluid (e.g., water) sanitization assemblies are useful in a myriad of different environments for various uses/applications, such as commercial and/or industrial applications. While such systems have various features and advantages, there is a constant need to improve the effectiveness of such systems. Accordingly, this and other needs are addressed by the systems and methods for sanitizing pool and spa water, of the present disclosure. 
     SUMMARY 
     Provided herein are systems and methods for sanitizing pool and spa water. In one embodiment, an electrolytic chlorinator (sometimes referred to herein as a salt cell) is provided which includes a combined flow, temperature, and salt concentration sensor. In another embodiment, the electrolytic chlorinator includes an acid tank for in-situ cleaning of the electrolytic chlorinator or acidification of pool/spa water where needed. In another embodiment, a delayed polarity reversal technique is provided for de-scaling and managing passivation of the blades of an electrolytic chlorinator. In still another embodiment, the electrolytic chlorinator includes a sacrificial anode for protecting components of the chlorinator as well as other pool/spa components. In yet another embodiment, the electrolytic chlorinator includes an integral, electrically-controlled acid generator. In another embodiment, the electrolytic chlorinator includes a brine tank for periodically superchlorinating and/or shocking pool/spa water. In still another embodiment, the chlorinator includes a plurality of chemical tanks/feeds for periodically injecting chemicals into the chlorinator. In another embodiment, a combined ultraviolet (UV)/Ozone and salt (electrolytic) chlorine generator is provided. In other embodiments, filters having integral UV sanitizers are provided. In still further embodiments, reflective linings are provided for UV sanitization systems. In another embodiment, a UV/Ozone sanitizer having means for injecting bubbles into pool/spa water is provided. In another embodiment, a system for acquiring and analyzing samples of pool/spa water using an unmanned aircraft (drone) is provided. Potential applications for the technologies disclosed herein include, but are not limited to, pools, spas, hot tubs, cooling towers, mister systems, secondary and tertiary waste water, rainwater, drinking water, industrial water treatment, aquaculture, and agriculture. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing features of the disclosure will be apparent from the following Detailed Description, taken in connection with the accompanying drawings, in which: 
         FIG. 1  is a diagram illustrating an electrolytic chlorinator having an combined flow and salt concentration sensor; 
         FIG. 2  is a diagram illustrating the combined flow and salt concentration sensor of  FIG. 1  in greater detail; 
         FIG. 3  is a diagram illustrating an electrolytic chlorinator having an acid tank for in-situ cleaning of the chlorinator and/or acid introduction into pool/spa water; 
         FIGS. 4A-4B  are diagrams illustrating a delayed polarity reversal technique in accordance with the system of the present disclosure; 
         FIGS. 5A-5B  are diagrams illustrating an electrolytic chlorinator having an integral sacrificial anode; 
         FIGS. 6A-6B  are diagrams illustrating an electrolytic chlorinator having an integral, electronically-controlled acid generator; 
         FIG. 7  is a diagram illustrating an electrolytic chlorinator having a brine tank for shocking and/or superchlorinating pool/spa water; 
         FIG. 8  is a diagram illustrating an electrolytic chlorinator having a plurality of chemical tanks and/or feeders for periodically introducing chemicals into the chlorinator; 
         FIG. 9  is a diagram of a conventional ultraviolet sanitizer; 
         FIG. 10  is a diagram of a conventional ultraviolet/ozone sanitizer; 
         FIGS. 11-12  are diagrams of an ultraviolet/ozone sanitizer and electrolytic chlorine generator in accordance with the present disclosure; 
         FIGS. 13A-13B  are diagrams illustrating filtration systems having integral UV sanitizers in accordance with the present disclosure; 
         FIGS. 14A-14B  are diagrams illustrating reflective inner surfaces for UV sanitizers; 
         FIG. 15  is a diagram illustrating a UV/Ozone sanitizer having bubble generation capability; and 
         FIG. 16  is a diagram illustrating a system for obtaining samples of pool/spa water using unmanned aerial vehicles (drones). 
     
    
    
     DETAILED DESCRIPTION 
     The present disclosure relates to systems and methods for sanitizing pool/spa water, as described in detail below in connection with  FIGS. 1-16 . 
       FIG. 1  is a diagram illustrating an electrolytic chlorinator  10  in accordance with the present invention. The chlorinator  10  can operate with a pumping system of a pool and/or spa, and sanitizes water of the pool and/or spa by converting salt within the water to free chlorine via electrolysis. The chlorinator  10  includes a body  12 , a combined flow, temperature, and salt sensor  14  that is removably installed in an aperture  16  in the body and extends into a chamber  18  of the body, a forward portion  20  which includes a plurality of electrolytic plates  22 , and ports  24 ,  26 . It is noted that the combined flow and salt sensor  14  is installed in the aperture  16  in the general direction shown by the arrow in  FIG. 1 . 
       FIG. 2  is a diagram illustrating the combined flow, temperature, and salt sensor  14  in greater detail. The sensor  14  includes a body  30  having a generally cylindrical outer wall  32  and a peripheral shoulder  34 , a chamber  36  that receives a circuit board and/or electronics, potting compound  36  which encapsulates the circuit board and/or electronics, a recessed portion  38 , a paddle wheel  40  which is at least partially positioned in the recessed portion  38 , and a plurality of electrodes (pins)  42 . As can be seen, 4 pins  42  are provided, but other quantities of pins could be provided without departing from the spirit or scope of the present disclosure. The paddle wheel  40  is in mechanical communication with a flow meter forming part of the sensor  14 , and rotates whenever water flows past the sensor  14  to measure the rate of water flow past the sensor  14 . 
     The sensor  14  measures the salt concentration in pool/spa water, as well as water&#39;s conductivity. Unlike 2-pin sensors, there is no interference from ‘fouling’ (e.g. scaling) and no calibration is required for the sensor  14 . The sensor  14  can be located inside a salt cell (electrolytic chlorinator or other piece of pool equipment—e.g. pump, heater, etc.). Locating the sensor  14  inside a salt cell (or other pool equipment) eliminates the need for the sensor to be plumbed somewhere else in the system. Also, it allows the salt cell to intelligently know to shut itself off—it can do this because a change of conductivity occurs when water stops flowing and the gasses generated by the salt cell start to void the cell of liquid. When the sensor  14  stops being surrounded by water, the conductivity changes dramatically and can be detected and used for salt cell control (to control the chlorinator  10 ). 
     The sensor  14  can be used for cell health monitoring and diagnostics. The measured salt level from the sensor  14  can be compared with a calculated salt level based on an algorithm involving cell voltage, cell amperage and water temperature. In the comparison between ‘measured’ and ‘calculated’ salt, it is possible to discern how the salt cell is performing versus how it should be performing—the difference can intelligently inform if the cell is dirty (and needs to be cleaned) or if the cell is permanently degraded (and how much lifetime remains). Another advantage of the sensor  14  is that it can be used, in combination with the volume of pool or spa water, to inform the user of the actual pounds (or kilograms) of salt that needs to be added to the pool/spa in order to raise the salt concentration to a target level. Further, the salt concentration measured by the sensor can be compared to an impedance of plates of an electrolytic chlorinator in which the sensor is installed to determine a difference, and a condition of the electrolytic chlorinator can be determined based on the difference (which can be monitored over time). 
     The flow sensor of the sensor  14  can measure the presence of flowing water and the actual water flow rate. Installation of flow sensor in a salt cell or other piece of pool equipment (e.g. pump, heater) eliminates the need for a separate flow switch to be plumbed somewhere else in the system. The rotation of the paddle wheel  40  can be bidirectional, permitting flow detection and measurement in either flow direction. Magnets on the end of each rotary vane of the paddle wheel  40  can be detected by electronics in potted housing  36 . The force required to rotate the paddle wheel  40  is very small, permitting detection of very low flow rates (e.g. &lt;10 GPM). The paddle wheel  40  is scalable and can be used in small pipe and large pipe diameters (e.g. ½ inch pipe to 8 inch pipe and beyond). Further, paddle wheel  40  eliminates failure modes that falsely report flow. Calculation of pool turnover (i.e. how many gallons of water was processed in a 24 hour period divided by the volume of the pool) is also possible using flow measurements. Calibration of pump RPM and pump energy consumption to the flow rate for a given pool pad arrangement can also be performed, allowing for the calculation of electrical energy used to operate pool daily/weekly, annually, etc. 
     Additionally, calculation of optimal mixing and turnover rates for improved chemical sensing and dosing algorithms (e.g. prevent over oscillation) can be performed. A display could be provided for displaying flow rate and historical flow rates in a chlorinator (or a pump or a heater). Further, sensor  14  eliminates filter schedules by filtering as long as needed to meet specific water turnover goals and at the best energy level (e.g. run as slow and as long as you allow the pool to run). The sensor  14  enables a combination of flow rate (and flow history) with pump power sensing to predict whether there is a system leak. If pool plumbing has a significant leak then pump energy could decrease dramatically at constant flow rate or pump energy could remain constant yet there be a dramatic increase in flow rate. Additionally, the sensor  14  enables a combination of flow sensing and pump relay in order to 1) build a hydraulic curve for the plumbing, 2) determine practical maximum flow rate, 3) determine turnover schedule requirements, and 4) sense the filter media health. Still further, the sensor  14  enables a combination of flow sensing and certain controlled equipment in order to dynamically set the correct flow to meet 1) heater requirements when heating, 2) chlorinator needs when chlorinating, 3) adequate mixing of dosed chemicals such as acid or liquid chlorine when dosing. 
       FIG. 3  is a diagram illustrating another embodiment of the sanitization system of the present disclosure, wherein an electrolytic chlorinator (salt cell)  110  with periodic in-situ acid cleaning capability is provided. In this embodiment, the chlorinator  110  is fed acid from an acid tank  128  via tubing  129  in fluid communication with a port  116  in the housing  112  of the chlorinator. A ‘cell cleaning cycle’ could be provided which automatically injects some (or all of the acid) that is expected to be needed (in a given week, for example) by the pool based on the salt chlorinator runtime and pool size directly into the salt cell to permit cleaning of scale from the salt cell. The system could inject a small amount of acid directly into cell  110  just prior to a pump turning on (e.g. 1 hour before), so as to take advantage of the high acid level on the electrodes yet rinsing it clean after this short exposure time. Alternatively, the system could inject a small amount of acid directly into cell after the pump has turned off to allow acid to soak inside cell and remove scale. 
       FIGS. 4A-4B  are diagrams illustrating a polarity reversal delay technique in accordance with the system of the present disclosure. The polarity reversal technique allows for removal of oxygen  134  from pores/cracks  138  in the surface  132  of a cathode coating formed on a titanium electrolytic chlorinator blade  130  (which could include a layer of titanium dioxide  136 ).  FIG. 4A  illustrates the condition of the blade  130  prior to polarity reversal, and  FIG. 4B  illustrates the condition of the blade  130  after polarity reversal. Most salt cells are controlled in such a way that the polarity is reversed at some frequency (e.g., every 1, 2, 3, 4, 8 hours) in order to allow for self-cleaning. The very act of switching the polarity causes an anode to become a cathode and vice versa. The chemistry switches also, because an anode has an acidic surface environment (i.e., chlorine gas production) and the cathode has an alkaline surface environment (i.e., hydroxide ion production). This aids in self-cleaning as calcium scale will precipitate on the alkaline cathode but gets dissolved by the acid environment when it becomes an anode. Another aspect of polarity reversal has to do with how much time delay, if any, occurs when the polarity is switched. It is advantageous to build in a time delay between the polarity switch (as opposed to a hard switch over with no time delay) because the cathode also produces a small amount of oxygen gas  134  that can combine with the underlying titanium substrate  130  to form a passivated titanium oxide layer  136 , which is non-conductive. The titanium passivation  136  (titanium converting to titanium dioxide) permanently prevents the electrode from functioning. The act of introducing a time delay is to allow the oxygen time to diffuse (convect) away so when the electrode becomes energized again there is less oxygen present to potentially form the oxide layer. A 1-minute delay between switching (with switching occurring every 3 hours) has been found to be sufficient, such that there is no detriment to overall chlorine production with a few minutes of downtime per day. It is possible that longer delays are better (e.g. 2 minutes, 4 minutes, 10 minutes) in that such delays would extend the life of the salt cell. These longer delays could be factory set or adjustable in the chlorinator control center by the end user. 
     Alternatively, a learning algorithm can be employed whereby the monitoring of the output of the cell intelligently informs the controller as to how long it is taking for the cell to become dirty with scale. A controller can then decide as to the frequency of the polarity reversals. For example, if the cell is not scaling much (due to low hardness water), then the controller does not demand polarity reversal every “x” hours. Instead, it learns how often to reverse based on how quickly the cell is scaling. 
       FIGS. 5A-5B  illustrate another embodiment of the sanitization system of the present disclosure, wherein a chlorinator  210  includes a sacrificial anode  229 . The sacrificial anode  229  could be attached to a plug  228  which inserts into an aperture  216  formed in a housing  212  of the chlorinator  210 , such that the anode  229  extends into a chamber  218  formed in the chlorinator  210 . Water flows into the chamber  218  in the general direction indicated by arrow B, past the sacrificial anode  229 , and past electrolytic plates of the chlorinator  210 . Of course, it is noted that flow direction could be reversed (in a direction opposite arrow B), if desired. Sacrificial zinc anodes can be used to help mitigate the galvanic corrosion damage done by stray currents that may exist in the water due to insufficient equipment bonding or insufficient pool grounding to earth. They can be also used to prevent a battery-like environment created between two dissimilar metals in contact with the conductive water (cathodic protection). Sacrificial anodes are wearable items and, after 6-months, 1 year, 2 years or more, the anode will need to be replaced as the zinc will have dissolved away. Zinc is used as sacrificial anodes in marine application extensively (e.g. to protect the hull of ships in salt/brackish water). Zinc happens to have some algistatic properties as well so its dissolution is desirable not only from the sacrificial anode standpoint but from the aspect that it provide an algistat to the pool water. 
       FIGS. 6A-6B  illustrate another embodiment of the sanitization system of the present disclosure, wherein a chlorinator  312  includes an integrated acid generator  329 . The acid generator  329  could be attached to a plug  328  which inserts into an aperture  316  formed in a housing  312  of the chlorinator  310  (in the general direction indicated by arrow C), such that the acid generator  329  extends into a chamber  318  formed in the housing  312  of the chlorinator  310 . The acid generator  329  could be powered by a power supply  330  in electrical communication with the anodes  329 . Salt chlorine generators naturally cause an increase in the pH of the water due to the net chemical reaction: 2NaCl+2H 2 O Cl 2 +2NaOH+2H 2 . To counteract the pH increase due to the sodium hydroxide production (i.e. NaOH), the acid generator  329  generates an acid (i.e. protons—aka H + —aka H 3 O + ), and could be formed from a pair of electrodes that can fit inside the chlorinator  310 . The acid generator  329  operates when the salt cell is operating in order to neutralize the pH change. Alternatively, or additionally, the acid generator  329  can be turned on just prior to the pump so the cell can be soaked in acid and cleaned of scale. Alternatively, or additionally, the acid generator  329  can be turned on after the pump shuts off so the cell can be soaked in acid and cleaned of scale. The acid generator  329  can be intelligently matched to the salt cell operation so that the NaOH is precisely neutralized. The acid generator  329  can also operate independent of the cell to lower the pH of the pool water when desired. 
       FIG. 7  is a diagram illustrating another embodiment of the sanitization system of the present disclosure, wherein a chlorinator  410  is provided which is fed by a brine tank  428  in fluid communication with the chlorinator  410  via a tube  429  to provide for superchlorination when needed. The tube  429  is in fluid communication with a port  416  formed in a housing  412  of the chlorinator  410 , such that brine is periodically injected into a chamber  418  of the chlorinator  410 . Pools and spas occasionally require a shock of chlorine (aka-superchlorination) to oxidize contaminants (e.g. organics, dead bacteria, metals, combined chlorine)). Salt chlorine generators generally do not make good superchloriantors because they generate chlorine too slowly. For example, a typical salt generator will make 1-2 lbs of chlorine per day but the superchlorination of a pool calls for raising the chlorine level to 10 ppm rapidly. A 40,000 gallon pool would need about 4 lbs of chlorine to raise it to 10 ppm (from 0 ppm) but that cannot be done quickly with a salt system. In order to enable the salt system to produce more chlorine, a higher salt level can be used. Raising the salt level in the entire pool would be undesirable. The brine tank  428  provides a high salt concentration into the salt cell so the cell can make more chlorine without needing to raise the salt level of the entire pool. The brine tank  428  (containing dissolved salt at a concentration similar to ocean water—30,000 ppm—or even higher—up to saturation level of salt in water at room temperature) is fed directly into the salt cell while the flow rate through the cell is reduced (this is to keep from diluting the introduced salt solution yet allowing flow to carry away chlorine gas). The higher salt concentration will allow the salt cell to make more chlorine and the salt cell can then serve as a means of superchlorinating the pool/spa. 
       FIG. 8  is a diagram illustrating another embodiment of the sanitization system of the present disclosure, wherein a chlorinator  510  is in fluid communication with a plurality of chemical feeders  528   a - 528   c  via fluid lines  529   a - 529   c . The fluid lines  529   a - 529   c  inject fluids from the feeders  528   a - 528   c  into a chamber  518  formed in the housing  512  of the chlorinator  510 . Many different chemicals are available to add to pools to control water quality issues such as high metals content, high phosphate levels, high organic load, high or low pH, high or low alkalinity, low cyanuric acid, low hardness, foaming, etc. All of these chemicals can be introduced in liquid form into the port  516  of the electrolytic chlorinator  512 . The chemical types and their functions could include, but are not limited to, the following: 
     
       
         
           
               
               
             
               
                   
               
             
            
               
                 Sequesterants 
                 Remove metals 
               
               
                 Chelating agents 
                 Bind metals, bind cations (e.g. 
               
               
                   
                 calcium) 
               
               
                 Defoamers 
                 Reduce foaming 
               
               
                 Fragrances 
                 Improve water odor 
               
               
                 Acid (e.g. muriatic) 
                 Lower pH, lower alkalinity 
               
               
                 Sodium carbonate solution 
                 Raise pH 
               
               
                 Sodium bicarbonate solution 
                 Raise alkalinity 
               
               
                 Cyanuric acid 
                 Chlorine stabilizer 
               
               
                 Calcium chloride solution 
                 Increase water hardness 
               
               
                 Sodium bisulfite solution 
                 Reduce excess chlorine levels 
               
               
                 Sodium bromide solution 
                 Algicide 
               
               
                 Hydrogen peroxide 
                 Oxidizer 
               
               
                 Metals solution (e.g. silver nitrate, 
                 Algistat, algicide, bacteriostat, 
               
               
                 copper sulfate, zinc nitrate) 
                 bacteriocide 
               
               
                 Chemical that acts as solar blanket 
                 Solar blanket-keeps heat in water and 
               
               
                 on surface of the water 
                 prevent heat escape 
               
               
                 Enzyme solutions 
                 Eats organic matter 
               
               
                 Phosphate removers 
                 Reduces phosphate levels that can 
               
               
                   
                 promote algae 
               
               
                 Algicides 
                 Prevent or kill algae 
               
               
                 Liquid Chlorine 
                 Sanitizer and oxidizer 
               
               
                   
               
            
           
         
       
     
     It is noted that a manifold could be constructed so that multiple feed tanks can feed into the same port  516  on the chlorinator  512 . 
       FIG. 9  is a diagram illustrating a conventional ultraviolet (UV) sanitization system, indicated generally at  600 . UV, Ozone and salt chlorine generation systems are all well-known methods to sanitize pool water. These technologies can be employed individually on a pool or spa in combination with each other. Some systems have been reported that combine UV and ozone into a single system using a UV lamp that serves as both the source of UV light for water treatment and ozone generation for water treatment. One example of such a system is shown in  FIG. 10  at  700 , which depicts an ultraviolet sanitizer system  704  that has ozone generation capabilities. Ozone is generated by the ultraviolet light of the sanitizer system  704 , is siphoned via a tube  706 , and is fed into pool/spa water to be treated using a venturi  702 . Such systems (shown in  FIGS. 9 and 10 ) could be further modified to include a salt chlorine generator, as indicated at  800  in  FIG. 11 . Such a system  800  includes an ultraviolet and/or UV/Ozone generator  802 , and a salt chlorine (electrolytic) generator  806  in fluid communication with the generator  802  by piping  804  and/or tubing  808 . It is noted that the salt cell (i.e. chlorine generating electrodes) can be placed directly inside the UV and/or UV/Ozone vessel, if desired. The advantages may include a smaller equipment footprint on the pool pad and the use of a single electronic controller. Since neither UV nor ozone can be used as a stand-alone sanitizer due lack of a lasting chemical residual, chlorine is required with either a UV or UV/Ozone system-hence, integration into a single product makes sense. 
       FIG. 12  is a diagram illustrating another embodiment of the sanitization system of the present disclosure, indicated generally at  900 . In this embodiment, the sanitization system  900  includes an ultraviolet/ozone (UV/O3) sanitization system  902  in fluid communication with an electrolytic chlorinator  908 . The electrolytic chlorinator could be controlled by an electronic controller  910 . The UV/O3 sanitization system  902  could include a venture assembly  904  which feeds ozone into water to be treated. Such ozone could be supplied via a tube  906  which draws ozone generated from ultraviolet lamps in the system  902 . A big benefit of using a UV and/or a UV/ozone and/or an Ozone generator with a chlorine source for pool and or spa water treatment is that the amount of chlorine needed can be much less-on the order of 50% less. Due to the lower chlorine output needed, the end user has at least 2 options when paring these systems with a salt water chlorinator: reduce the operating time of an existing salt system (say by 50% for example) and, as a result, extend the duration of the use of a salt cell by a factor of 2, or, pair the UV, UV/Ozone, or Ozone system with a LOW SALT chlorine generator. The lower salt level will: 1) reduce the chlorine output of the salt chlorine generator; and 2) will lower the risk for corrosion of pool decking, pool equipment and poolside furniture. LOW SALT is defined as being less than 2500 ppm, preferably less than 2000 ppm and most preferably less than 1500 ppm. 
       FIGS. 13A-13B  are diagrams illustrating another embodiment of the sanitization system of the present disclosure. As shown in  FIG. 13A , the system  1000  includes a filter  1002  and an ultraviolet sanitization system  1004  positioned within the filter  1002 . A manifold  1006  could control water flow through the filter  1002 , and could provide a mounting point from which the ultraviolet sanitization system is suspended. As shown in  FIG. 13B , the system of  FIG. 13A  is expanded (indicated generally at  1100 ) to also include an ozone feeder system that includes a venturi assembly  1108  and a tube  1110  for feeding ozone into water to be filtered. The ozone could be supplied by an ultraviolet assembly  1104  positioned within the filter  1102  and suspended from a manifold  1106 . 
     Manways or “manhole covers” can be placed on filter housings for easy access to media servicing or replacement (e.g., as in sand filters). The manway can serve as the access point for the insertion of one or more UV lamps. The only requirement of the final system is that the water is filtered prior to passing the UV lamps—this is because UV works best when the water is clear. Furthermore, filtered water is less likely to foul the glass sleeve that is placed around the lamp. 
       FIGS. 14A-14B  are diagrams illustrating ultraviolet sanitization systems which include reflective liners. As shown in  FIG. 14A , the sanitizer  1200  includes an ultraviolet lamp  1204  and reflective liner  1202  which reflects light into the sanitizer  1200  as indicated by arrows D. A conventional sanitizer  1300  is shown in  FIG. 14B , which lacks a reflective liner. As can be appreciated, only direct light emanating from the lamp  1304  is available to sanitize water, as indicated by arrows E. UV reflective surfaces allow a portion of the UV light to return to the water column where it can provide additional benefit in the way of microbial inactivation. Some UV reflective materials that could be utilized for the liner  1202  are listed below: 
     
       
         
           
               
               
               
             
               
                   
                   
               
               
                   
                 Material 
                 UV Reflectivity 
               
               
                   
                   
               
             
            
               
                   
                 Plastic 
                 10% 
               
               
                   
                 Polished stainless steel (SS) 
                 30% 
               
               
                   
                 Polished aluminum 
                 60% 
               
               
                   
                 Teflon (PTFE) 
                 &gt;99%  
               
               
                   
                   
               
            
           
         
       
     
     No system exists whereby a highly reflective coating (i.e. greater than polished SS) has been added to the vessel wall of a UV/ozone water treatment system. Such a system has the benefit of the returned UV light to the water column where it can convert ozone to hydroxyl radicals—or at the very least—destroy the ozone so it does not return to the pool or spa where off-gassing of the ozone can harm bathers 
       FIG. 15  is a diagram illustrating another embodiment of the sanitization system of the present disclosure, indicated generally at  1400 , which introduces air or gas bubbles into water to be treated. In this embodiment, the sanitization system  1400  includes a combined UV/O3 sanitization system  1402 , a venture assembly  1404 , and an external supply  1406  of air or another gas for sanitizing water being fed into the system  1400 . The addition of an air bubble (irrespective of the gas composition in that bubble), causes the UV light to reflect/diffract off the bubble surface thereby increasing the mean path length through the water column before the UV hits the reactor wall where the majority of its energy is lost as heat. 
       FIG. 16  is a diagram illustrating another embodiment of the sanitization system of the present disclosure, which includes an unmanned aerial vehicle (UAV) or drone  1500  that can fly toward a body of water such as a pool or spa  1512  (in the direction indicated by arrow F) and periodically obtain a sample of water  1510  from the body of water. The drone  1500  could include a body  1502 , propellers  1504  for propelling the drone  1500 , and a water sampling device  1506  for obtaining samples of the water  1510 . The drone  1500  could transport the sample of water to a testing facility whereby the water is tested for various characteristics such as water quality, pH, chlorine levels, bromine levels, etc. Alternatively, the drone  1500  could include sensors for automatically testing such characteristics on-board the drone  1500 , so that the drone need not fly to a testing facility. 
     For the vast majority of pool and spa owners, a proper water analysis is conducted by the end user bringing a water sample to a local retail or service store where specialized equipment is available to evaluate the water quality. Water quality parameters such as pH, free chlorine, total chlorine, combined chlorine, bromine, calcium hardness, total alkalinity, total dissolved solids, cyanuric acid, phosphate levels, metals (such as Fe, Mn, Cu and Ag), and salt (i.e. sodium chloride), are commonly measured. Many of these measurements are beyond the scope (and affordability—as analytical equipment can be expensive for a homeowner) of what is available to the consumer to perform at their home. Most consumers, if they make measurement themselves will use simple test strips or simple dropper kits. The tests trips measure free chlorine, total chlorine, pH, total alkalinity, total hardness, cyanuric acid and pH whereas the dropper kits typically are limited to pH and free and total chlorine. The inconvenience of bringing a water sample to a store can be alleviated by the use of the drone  1500  which flies to the location of the pool and/or spa and gathers a water sample. The drone is outfitted with a means to gather and store a volume of water, typically 2 mL or more, preferably 5 mL or more, and most preferably 10 mL or more. The collected water sample can be brought back to a water testing location for analysis or, given sufficient onboard sensors, the drone could analyze the water, including temperature, at the point of pick up. In either case, the results can be sent to the homeowner or a service company for immediate action should any of the water quality parameters fall outside of recommended guidelines. The drone could be outfitted with GPS or equivalent to locate the body of water. Furthermore, the drone can have onboard sensors, protected from the elements within its housing, that detect whether the pool or spa has a cover on it and whether or not there are active bathers in the water. In the event of active bathers, an audible alarm could warn of the impending water landing, or alternatively, the drone can ‘reschedule’ its visit or manage to descend without approaching closer than 10 feet to a bather. Finally, the drone can have communication capability (WiFi or other) that allow it to be manually guided or rerouted as deemed necessary by the sending party. We can imagine that the sender is managing the flight of the drones in a manner similar to the tracking of airline flights by air traffic control. Additionally, the onboard communication of the drone can alert the end user (by text or email) when it intends to be at their location and can then communicate the results of its findings. On-board sensors could also be part of the drone that enable it to test turbidity and sense physical debris in the water, using cameras for example, so it can alert appropriate parties as to the need for added filtration or filtration maintenance as well as pool cleaning services. The drone could direct an automatic pool cleaner to certain top, side and bottom locations for debris removal as well as instruct a pool automation system on filtration cycle management, chlorination output, heater control, etc. 
     Additional features of could be provided in accordance with the present disclosure as follows. 
     If a salt chlorine generator output varies with salt level, water temperature, current supplied or other external variable, then a fixed amount of chlorine per day can be maintained by sensing chlorine generator amperage versus the amount of chlorine generator runtime and then keeping the filter running (or intentionally shortening its on-cycle) to match the targeted daily chlorine dosage. A system could be provided wherein chlorine generator production rate is modified with water temperature to match higher chlorine demand in hotter water versus lower chlorine demand in colder water. Such a system could combine amperage utilization by chlorinator with pump schedule to predict chlorine dose provided by the schedule. Further, such a system could modify chlorine dosing (salt system or liquid or tablet chlorine feeder) with weather reports and geographies (e.g. hot in AZ combined with wind creates more dust in pool; anticipate temp at night to assess overall chlorine demand). 
     In a salt chlorine generator, a system could be provided wherein the generator modifies polarity reversal rates of the chlorine generator based on water hardness, water temperature, age of salt cell and flow rate. 
     Various smart sensing and control techniques could be implemented in accordance with the present disclosure. For example, such techniques could involve the use of predictive trends of water quality data (e.g. pH trend line) to determine dosing regimen rather than simple timeout features (Example of old method: Acid feeder is activated due to high pH. After several hours the pH target still not met so a timeout alarm is used to stop what may be a bad pH probe and overdosing of acid. Example of new method: Acid feeder is activated due to high pH. After several hours the pH target still not met but the pH trend line is going as expected and so dosing continues). Such a method eliminates false alarms and inconvenient timeouts. Additionally, the system could modify/compensate ORP set point with measured pH value. Since ORP drops as pH increases, a potential exists to continue adding chlorine when in fact ORP only dropped due to pH and not due to insufficient chlorine. The issue of falling ORP with rising pH is currently problematic with salt chlorinators managed by ORP sensing because the pH will rise as the chlorine generator operates, causing a lowering of the ORP and the potential for the ORP not to hit its set point, calling for more chlorine when in fact there is plenty. Still further, the system could modify/compensate ORP set point with sunlight. UV/visible rays have a pronounced effect on ORP if cyanuric acid is used. For example, at the same chlorine level, water exposed to darkness will have a higher ORP than the same body of water exposed to sunlight (because cyanuric acid will bind the chlorine more tightly in the sun—has to do with the binding strength between the chlorine molecule and cyanuric acid molecule as a function of UV/visible light). 
     The system could also be embedded with a reminder system in the equipment (chlorinator, pump, etc.) to recommend manual water tests. A calculator/wizard could be used to recommend ORP set points and chlorine dosing based on manual water tests. Further, the system can calculate acid needed to offset pH rise when using a salt chlorinator as a function of water chemistry parameters, chlorinator runtime, geography and weather reports. For example, the pH rise in a given week/month associated with specific chlorinator usage can be predicted for a given pool given its volume and water chemistry. If however, acid rain occurs, the need for additional acid may be nil in any given period. Other water parameters that could be sensed include alkalinity, cyanuric acid levels, and calcium hardness levels. 
     Additionally, further improvements can be made to salt chlorinators in accordance with the present disclosure, as follows. Salt chlorine generators typically are designed to shut off when the water flow stops. That is, they are controlled by a flow switch that triggers the shut off. In doing so, a high concentration of chlorine exists inside the cell which can diffuse upstream and chemically attack heaters and other pool equipment. For this reason, a check valve is often used upstream of the chlorinator to prevent this backflow. A better solution is to simply have the chlorinator shut off 1 or 2 minutes before the pump—in this way, the salt cell has been flushed of the high concentration of chlorine and only normal pool water chlorine levels exist inside the cell-therefore no check valve is needed. Note that the volume of a salt cell is small compared to the volume of water flowing through it so only a few seconds of ‘flushing’ is needed after the cell shuts off. 
     The systems of the present disclosure could also include the ability to predict the need to shock or superchlorinate a pool or spa. Shocking or superchlorination of pool water is periodically required to oxidize bather waste. The system can anticipate the need to shock based on weather (e.g. sunlight, rainfall), bather load, turbidity, seasonality and combined chlorine level. 
     Additionally, in accordance with the present disclosure, the various UV/Ozone systems disclosed herein could also be modified to function as bromine generators. Bromine is commonly used in hot tubs because it does not form bromamines, unlike chlorine which forms malodorous chloramines. Bromine can be added to a hot tub by 1) bromine tablets, 2) by the generation of bromine using a salt bromine generator (starting with NaBr instead of NaCl as is done with chlorine) or 3) by generating the bromine in situ using ozone (a strong oxidizer) to convert bromide salt to bromine (Note: ozone will convert bromide to bromine. Bromides are introduced into hot tub as the NaBr salt). The hydroxyl radicals generated from a UV/Ozone system can be used to convert the bromides salt to bromine. The use of a UV/Ozone system not only regenerates bromine form the bromide ions but it reduces the amount of bromine needed to the overall sanitizing and oxidizing power of the UV/Ozone combination. 
     Still, further, in accordance with the present disclosure, pool lights or wall fittings can serve as turbidity and bather sensors. A pool light by definition is a transmitter of light. A pool light or wall sensor that contains a ‘light receiver’ can be calibrated using ‘clear’ water and the change in light intensity can be used to monitor the presence of bathers and/or changes in the turbidity of the water. 
     Having thus described the invention in detail, it is noted that the foregoing description is not intended to limit the spirit or scope of the present invention. Accordingly, what is desired to be protected by Letters Patent is set forth in the following claims.