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Were you just pointing at another hype with UV. That part confused me is all. In case you were wondering I was talking about coronal discharge ozonators, not UV light bulb ones. And it was my understanding that the UV never touched the water. UV reacts with chlorine in a way that produces THMs I wasn't aware of any ozone related problem. Was the high electrical consumption due to the ozone? Or the demands of a gigantic filtration system? The largest residential Coronal discharge ozonator in the product line I've bought into uses about 30 watts. That's chump change compared to ANY pump which can easily break 1000w! I haven't looked into UV but I can't imagine it being much worse. Salt chlorination probably use more electricity in the summer with UV eating up chlorine levels. Though commercially you'd be required to remove the ozone, I don't see any benefit residentially. As long as you didn't run the ozonator while you were swimming even ludicrous amounts of ozone would be completely gone in about two hours after the ozonator was turned off. So I guess I'm not seeing your point about filtering ozone. I know they had to filter it but what about me? Why would I have to?

A two speed pump wouldn't be efficient for an ozone system. Ozone never makes it too the pool or the bather area. The first paragraph or so of my post goes over why. So in an "ozone only system" a high turnover is the only way to keep the water fully sanitized. You have push most or all of the water through ozone for it to be effective. But even this will not prevent algae growth on the surfaces of the pool. (Again ozone never makes it to the pool, and algae that starts growing on the walls never makes it to the filter/ozone. So it's not effected). Additionally, though you may have turned over the volume of the pool in your system there will always be eddies and areas of the pool that are not circulated by the pump. So, in a residential system chlorine/algaecide are REQUIRED. They are not optional. Algaecide in a commercial system is still required even with a "perfect" ozone system. HOWEVER, this does not mean you need to use as much chlorine. In fact using to much is not only useless it's detrimental! The additional chlorine will react with the ozone and then you've just defeated the purpose. The purpose is that ozone is a super powerful oxidizer and, with proper maintenance, should allow me to use less chlorine. Additionally, because it reacts with things that chlorine doesn't (algae food, phosphates, anything organic) and it does so in a way that allows clarifier to easily bond with those particles, it will help me keep clearer water. I have a sand filter so tiny particulate is currently a problem. From what I've read it won't be soon enough. I do not have a liner pool. And a salt pool brings all new issues with galvanization and corrosion of metals. Not from the salt, but from the electrolysis and current leakage required to convert it into chlorine. The only way to prevent that reliably is to add in a sacrificial zinc anode somewhere near the chlorinator. I've though about it but I'm not convinced that just a reasonable amount of attention and upkeep couldn't do just as well. Finally, bulbs are not an issue any more. Any ozonator worth buying should be a Coronal Discharge ozonator. From what I've ready they can produce enough ozone to get the job done. Replacement cartridges are about $100 bucks. If I save one bucket of chlorine a year I've paid maintenance. The unit in total is about $800. If I save a bucket of shock a year for 8 years I've made my money on that. And even if I spend extra to have an easier time keeping clearer water, I've gotten a priceless result. What I'm after is anyone who's had personal experience with properly operating a coronal discharge ozonator. What have they learned in practice?

I've tried to dig up as much information as I could before jumping into ozone sterilization. I think I've gotten enough research done to convince me that it's not a bad idea for my situation but I'm hung on a few details. First of all, from all of the research, I've read that there are many systems in Europe, and some systems in America that ozone fits very well into. For the most part these are commercial installations with a mixing basin where the ozone is dissolved into the water so it can be returned to the pool sterilized with minimal to no bubbling. Also I've learned that ozone works much better with higher rates of turnover. That is more water going through your filtration system quicker. I'll explain this later. Finally, when in use residentially I've learned retro-fitting a system makes it tough to use ozone entirely. The problem is that ozone is highly toxic. So it can't exist in any meaningful concentration in the pool itself. Meaning it has to be used as part of the filtration system. This lends itself to commercial systems that often run 24/7 but not to residential systems that may see 4-5 hours of filtration a day and only 2/5ths of the water actually turn over. That is to say 2/5 of all the water in the pool actually goes through the filtration system in that 4-5 hours. This brings me to the first bit of research. Effectiveness. Ozone is the most powerful natural oxidizer known to man. It completely obliterates anything organic it touches. Making it dreadfully poisonous and incredibly effective. Improperly handled ozone can be damaging to humans in amounts of as little as .1ppm and immediately hazardous and life threatening in amounts of as much as 5ppm! But because of it's ability to readily react with nearly any organic compound it also is easy to make safe. It breaks down very quickly in our natural world, because there are so many things for it to react with. So with the proper attention and a safe understanding it can very easily be controlled. Ozone exists as a pollutant in low atmosphere primarily because of exhaust fumes and UV light's reaction with many other known pollutants. Essentially, UV reacts with these volatile compounds to form ozone. Though the ozone immediately reacts with the next organic substance it touches it's still considered a pollutant because if it happens to touch your lungs, you are in a bad spot. Ozone is used in hospital air systems. It's a natural by-product in many copy machines, of lightning, and ultraviolet light. It's all over the place essentially. It's important to remember that ozone in concentration will hurt you. Just like chlorine or bromine or any other chemical used to annihilate all things living in your pool. The goal in pool sterilization, after all, is to poison the water just enough that most organisms can't live in it, but not so much that it instantly kills anything that touches it. Most systems sold residentially are safe simply because they don't produce enough ozone, that when used properly will hurt humans. Instead the ozone reacts with the stuff in your pool, just as it's supposed to. Just like sticking your head into a bucket of chlorine shock is harmful, plugging your nose with the output hose of a ozone generator is equally if not moreso harmful. So, because of ozone's effectiveness as an oxidizer, if you can get it into the water quick enough and with enough volume it's effectively like shocking your pool with some different effects. For example, ozone doesn't like to react with plaster or metals, but it will eat up your rubber pool gear in a heartbeat. Chlorine has the same effect but it's not as strong of an oxidizer so it will just take a bit more time than ozone might. If it were possible to put ozone into your pool with the same concentration as you shock your pool, you'd completely annihilate anything living in it. Though it wouldn't be safe to even be around your pool, much less swim in it. Therefore, to get the same effect as shocking your pool now you generally need much less ozone concentration to perform the same general function. Chemically this makes sense for pools because of what ozone will react with. Ozone reacts with many things chlorine doesn't including stuff that bacteria and algae like to eat, once these things are broken down they can be more easily processed by clarifying agents and filter resulting in the "clearer water" testimonials you've heard. At the same time there are things chlorine will kill that would take unsafe levels of ozone to kill (algae, some bacterial spores, bigger bits of organic matter). For these you'd need to supplement somehow in an ozone system to make up the difference, but I'll get into that later. http://www.poolsolutions.com/tip48.html You've heard that ozone never makes it into your pool, by and large that's true especially for older UV generators. The fact is that many older ozone generators weren't capable of generating enough ozone to get into your pool, these days that's simply not the case. Properly installed, today ozone DOES get into your pool. But with chlorine/bromine, additional contaminates, and it's inability to be constantly added to overcome these losses, not very much of it makes the trip. Additionally, the stuff that does make the trip quickly reacts upon entering the pool. The primary reason for this is safety, but in other ways it's simply impractical. Ozone reacts and breaks down too quickly to simply "leave" in pool water it would take quite a system to manage to effectively keep enough ozone in the pool water to sanitize it there, aside from the obvious safety issues this would cause. Agian, even in completely ozone sanitized commercial systems, the pool never has enough ozone in it to harm anything. Instead it's forced in just before filtration in high concentrations, then removed again and recirculated before eventually being safely vented as by-product. All of the sanitation takes place in the filtration system, the pool itself would go completely bad in a matter of days without filtering. That said, let me talk about solubility. http://www.ozoneapplications.com/info/ozone_properties.htm Ozone can be dissolved in water with about the same concentration as naturally occurring oxygen. However, this is largely dependent on air pressure and temperature. With the largest, and most variable factor being temperature. Most swimming pools rarely exceed a water temperature of 30 degrees celsius. That being said typically the MOST ozone that can be dissolved in water at that temp is about 8 ppm as compared with typical oxygen molecules. This concentration is inversely proportional to the temperature and altitude. That is to say the lower the temp or altitude the more ozone can be stored in water. Now this storage has a short term lifespan. At that same 30 degree water temp, not only can less ozone be stored in the water, but it "self destructs" more quickly. This is measured in a 'half-life' or the time it takes for the ozone to deplete by half. This is not counting ozone coming into contact with a particle it will oxidise. Even in the perfect world you'll never have ozone at 8ppm in a pool. And rightfully so as the ozone leaving the water would be deadly! At 30 degrees this half life is about 12 minutes. If you had your pool fully saturated with ozone (8ppm) then turned off the equipment, 12 minutes later the ozone levels would have depleted by AT LEAST half (4ppm). 12 minutes after that you're looking at 2ppm, another 12 you're at 1ppm etc. Even at 25 degrees the half life only increases to about 15 minutes. Meaning an hour after you've turned your pump off your ozone is for all practical purposes, completely gone. This is assuming conditions that are impossible to reach, much less maintain. The good part about this is that high enough levels of ozone can be produced to have the desired effect (killing and destroying everything you hate) in your piping. But by the time it gets to your pool it's EXTREMELY unlikely to persist in any concentration high enough to do anything, beneficial or detrimental. The bad part about this whole interaction is that in order to run your pool completely off of ozone you'd need to run your pool equipment almost 24/7. I'm thinking at least 8-10 hours a day with typical swimmer load on an indoor pool or well cleaned pool. Additionally, to get that kind of efficiency you'd almost certainly have to have bottom jets installed to help evenly distribute return water or more likely, have the pool designed to use ozone specifically. In short, it takes a pool designed to have high turn over rates (lots of moving water) all day long. This is the single biggest reason ozone has failed to catch on residentially. In order to make it work you need a system that runs all the time. But why would you ever want to do that if you don't swim in your pool all the time? Hot tubs, however, are a different story. Because of the high turnover rates, you can eradicate everything in your spa very in as little as ten minutes because ALL of the water in the tub runs through the ozonator in that time. And even though it reacts its way out just as quickly, the hot tub is effectively a closed system with the cover on it. Once the contaminates are taken care of new threats can't enter the system until the cover is removed again. I can see a world where ozone can easily eliminate chlorine use in hot tubs and the residential market seems to back me up. So, if ozone won't stick around can't I use chlorine to supplement it? Yes and no. From my reading ozone reacts relatively quickly with chlorine effectively rendering both oxidizers useless. So while ozone is being introduced not only will it have to be introduced in greater amounts, but at the same time it's eating up your chlorine and that portion of each product is going to waste. I've read from some that bromine is a better "buddy" to ozone and "works with it" in some ways. This may be true, but it also reacts on the order of 10-100 times more readily with ozone. Meaning this particular problem is all the more true. In short. While you're putting ozone in the water, it's blasting itself and your other oxidisers! http://stason.org/TULARC/science-engineeri...fect-ozone.html So what's the solution? By the time ozone reaches your pool, we've established that it's either non-existent or will quickly be eradicated. But while it's in the pipes it essentially does the work of a good shock. It is handily and efficiently eradicating all kinds of annoying pool buggers. The pool is largely a stagnate basin no sanitizer enters but nothing bad returns either. I'm thinking the way to keep the pool from becomming a cesspool is to keep 2ppm or less of chlorine in it (as typically directed) and to use a maintenance dose of algaecide in hot weather. The chlorine will get much of the initial junk that enters your pool, while your ozone will quickly blast apart bacteria, food, oils, and algae as water is recirculated. And the algaecide will work to keep algae from finding a happy home in one of the secluded crannies of your pool. How do I keep chlorine in my pool if it's being blasted by ozone? Three words. Good Chlorine Floatie. This will do two things. The first is to naturally introduce more chlorine when the pool is running. The second is to keep introducing chlorine where it's going to be in the most demand (the top of the pool). UV breaks down chlorine treatment quickly. Additionally, your fresh ozonated water will be returned near the surface as well. You want to chlorinate that water as quickly as possible upon return and let the chlorine do it's job. At some point I plan to find one a solar pumping chlorinators, it pumps a little trickle of water through the tablet chamber during the day to force water over the chlorine tabs. That should push out chlorine during the day, and at night (when electricity is in low demand and cheapest, and also when chlorine isn't being blasted by UV, I time the pump to start. Ozone cleans all night, the next morning the solar chlorinator starts it's job again and round we go. Talking mostly about Coronal Discharge ozonators. Does anyone have personal regular experience with these systems? Do you see a benefit when you reduce chlorine treatments? Do you still use shock? Is there any clarity difference? What comments do you have?