Does any one have any experiance with an ionization system on a high bather load commercial pool. I would like to hear from the group on this subject
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Does any one have any experiance with an ionization system on a high bather load commercial pool. I would like to hear from the group on this subject
You need to be a member of Pool Genius Network to add comments!
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Thanks Richard, saved me some typing and I've had a heavy day!
Without going into too much detail Mark, by now from Richards excellent links it should be clear that there really isn't much point considering the cost, of having an ioniser. I use one as an experiment on a vinyl pool and control the concentration very tightly. I would never use one on a plaster/tile/concrete pool, just too risky. I haven't measured the pH in the return lines but will make a point of doing so soon. I run my pool at 7.2 and have more problems with staining from sun cream than copper. The standard cleaning regime of brushing the pool walls produces a high pH right at the walls suface as the action of brushing exposes fresh plaster, I don't know how epoxy grout would react.
In the 8 years I have run the ioniser on a couple of occasions the chlorine tanks have run out and the operatives didn't notice for a while, whilst I have no proof other than test results the pools remained completely clear of algae and were very easy to bring back into chlorinated safety, usually just picking up from where I left off.
I run my pool at 0.2ppm chlorine, 0.4ppm copper, pH 7.2 and no CYA. I use a replacement for CYA that doesn't diminish the chlorine protects against UV loss and increases the redox potential but that's another experiment on going.
Copper forms copper oxide-hydroxides-carbonates (as does iron), but the actual pH when this occurs depends on the metal ion concentration (see copper hydroxide, copper oxide and copper carbonate). Also, some metal ion systems/products come with sequestrants that inhibit metal staining, but they also inhibit the effects of the metal ions as well (something they don't talk about). Adding a hypochorite source of chlorine or a pH Up (sodium carbonate) product may create temporary local conditions for the metal to precipitate and are the primary reason why adding such products can turn the water green (especially a "clear green" which is most indicative of copper instead of "cloudy green" for algae -- note that yellow iron on a blue vinyl background looks green and if often confused with copper or algae). In fact, one can sometimes use this technique to add pH Up into the skimmer to force precipitation of metals into the filter.
Plaster surfaces tend to be higher in pH and more susceptible to metal staining. So to avoid the aforementioned problems, either the metal ion level is kept lower or the pH is kept lower. ECOsmarte, for example, recommends a pH of 7.0-7.2 with 0.4 ppm copper ion level (see this link).
John,
I read in your post last Friday where you stated that cooper ions fall out of solution at a pH of 8.3 or higher. Although I am willing to accept this, could you please explain how or why that happens.
Assuming that this is true, then the use of a cooper/silver ionization system in a commercial pool that uses a hypochlorite type of chlorine product or even a salt/chlorine generation system, would be for all practical purposes be useless, as some of the copper ions would fall all out of solution everytime the feeder injects the chlorine into the return lines. Additionally, pools that need to use Soda Ash to raise pH would have significant amount of cooper ion fallout every time it is used.
So if in fact cooper ions will fall out of solution at a pH of 8.3 or higher, then all that is accomplished by the use of a cooper/silver ionization system on a high load commercial pool is a great way to stain the interior surfaces of the white plaster pools.
Is there any potential benefit for the cooper ions that have fallen out of solution and attached themselves to the surface of the pool interior to aid in the control of bacteria; and if so is the benefit less than when the ions were in solution?
I am really looking forward to a reponse to these questions.
Karen, what a wonderful idea! Given the cost of copper per pound, I think my boss would be willing to make our high bather load facility a test location for your claims. If your employer is willing to line our pool walls with copper (and if you think we should do the pipes too, no limits - we'll do it all!) at their cost, we'd love to try it out. Copper lined pool, copper pipes, copper filter, pump housings, impellers, etc. As long as you pay for us to try a $3,000,000 solution to a problem a $12,000 UV system might solve, we'd love to try it! If you want to make claims and link a few studies, prepare for them to be examined by a few sets of very critical eyes. If your employer is interested in giving a complimentary trial of your technology, let me know and I will give you my contact information!
Yes Karen copper will do all those things, are you proposing we build copper walled swimming pools as that is the only way what you have described will work. The problem with copper is the ability to stain ordinary pools and peoples hair if allowed in too higher concentration, the sort of concentration you need to achieve the results you have posted.
The small amount of copper ions introduced via an ioniser is just enough to assist with algae and some bacteria control but the level has to be tightly controlled or problems will happen and on a plaster/tiled/concrete pool that happens much much easier. Whilst staining is only cosmetic, generally people don't like the stains.
Slightly off topic, whilst copper may help with inflamation in arthritis, copper has also been linked to the spread of cancers as copper helps develop new blood supply paths to feed the tumour.
Karen,
You can quote all you want from the manufacturer's and industry trade organization websites, but so far you haven't referenced anything relevant to swimming pool disinfection or more specifically to this thread, prevention and/or removal of biofilms using copper/silver ionization in conjunction with chlorine.
While copper surfaces have a high enough concentration and differing mode of action to kill E.coli slowly, this is not true for copper ions at concentrations found in pools. The following scientific peer-reviewed papers in respected journals show that copper ions at the low concentrations allowed in pools do not inhibit let alone kill fecal bacteria (including E.coli) and are ineffective against many viruses as well:
http://www.sciencedirect.com/science/article/pii/004313549400213Q
"no inactivation of E. coli was observed after exposure to 0.4 or 0.8 mg/l cupric chloride after 60 min".
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2258564/
This paper showed a 3-log reduction in E-coli (wild-type strain) in 1 minute only above 500 mM (31,773 mg/L or ppm copper), but one cannot extrapolate here because E.coli cells have a mechanism for handling copper ions at a certain rate and therefore concentration (i.e. at low concentrations copper ions don't have any measurable kill effect).
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC95116/pdf/jb002145.pdf
This paper gives a MIC (minimal inhibitory concentration) of copper ions of 1.3 mM to 3.5 mM depending on strain, but even 1.3 mM is 82.6 ppm copper.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC241505/pdf/aem00153-005...
This study shows E. coli injury after 2 days reaching 90-99% after 5-7 days, but this injury is not death of coliforms and rather causes an underestimation of coliform counts, but that these cells can recover and grow (basically, coliform counts using growth medium with sodium deoxycholate would kill more injured cells, but nonselective TLY agar would not and resulted in high coliform counts; that is, bacterial viability remained high at over 90% even after 7 days of exposure to copper).
http://www.nrcresearchpress.com/doi/abs/10.1139/m87-010
This paper elucidates the mechanism for injury to decreased oxygen utilization, but again does not result in death of the cells and that they can recover and reproduce.
http://aem.asm.org/cgi/content/full/69/4/2313
This paper for Pseudomonas aeruginosa gives a MIC (minimal inhibitory concentration) for copper ions of 2 mM (127 ppm) copper though even lower 0.06 mM (3.8 ppm) copper showed only a significant lag of around 20 hours before growth occurred to normal levels by 30 hours.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1563648/
This paper showed the MIC (minimal inhibitory concentration) for copper-sensitive strains of Enterococcus faecium of 4 mM (254 ppm copper) so 0.4 ppm copper would have no effect on this bacteria and it is presumed that this is also true for Enterococcus faecalis.
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2798663/
This paper showed the MIC (minimal inhibitory concentration) for Staphylococcus aureus of 200 µM (12.7 ppm) copper so 0.4 ppm copper would have no effect on this bacteria.
http://aac.asm.org/cgi/reprint/41/4/812.pdf
This paper shows that copper ions do a 90% inactivation of Herpes Simplex Virus in 30 minutes at 100-200 ppm (copper is normally < 0.5 in pools and I use 0.4 ppm in the table above)
http://mic.sgmjournals.org/cgi/reprint/35/1/75.pdf
This paper shows no inactivation of vaccinia virus with copper alone at 5 µg/ml which is 5 mg/L (ppm).
http://www.ncbi.nlm.nih.gov/pubmed/1322762
This paper gives values for log10 reductions per minute with 0.3 ppm chlorine vs. 400 µg/L (0.4 ppm) copper and 40 µg/L (40 ppb) silver for coliphage MS-2 and poliovirus type 1. For a 3-log (99.9%) reduction in coliphage, we have (3/4.88)*(0.3/0.1) = 1.8 minutes using 0.1 ppm chlorine, (3/0.023) = 130 minutes for the copper/silver combination. For a 3-log reduction in poliovirus, we have (3/0.036)*(0.3/0.1) = 250 minutes using 0.1 ppm chlorine, (3/0.0006) = 5000 minutes for copper/silver combination (so I designate this as "> 5000" for copper alone).
http://www.springerlink.com/content/3234874542k7075x/
This paper showed that copper and silver alone, at ratio of 400:40 to 800:80 µg/l (ppb) caused no significant inactivation of N. fowleri even after 72 hours of exposure (k = log10 reduction/min = 0.00017 and 0.00013, respectively).
http://journal.kansensho.or.jp/Disp?pdf=0780020138.pdf
This paper showed that with 0.25 to 3 mg/L (ppm) copper ions there was perhaps a 0.5-log reduction in Cryptosporidium parvum oocysts after 12 hours.
This post I wrote gives further details for kill times of chlorine vs. copper and silver at pool concentrations. So please stick to relevant science when discussing these issues. Also, please fully disclose your background and why you are defending copper. I do not work in the pool or spa industry and have no financial interest in promoting one product or system over another.
Copper has been used as a medicine for thousands of years including the treatment of chest wounds and the purifying of drinking water. More recently, research has indicated that copper helps prevent inflammation in arthritis and similar diseases. Recent scientific investigations have also demonstrated the efficacy of copper to inactivate (kill) harmful microbes. These include L. pneumophila, the principal agent of Legionnaire’s disease, methicillin-resistant Staphyloccous aureus (the deadly pathogen that has become a primary concern for health care administrators), E. coli (a food and waterborne bacterium that causes severe illness and death) and Listeria monocytogenes, a bacterium that originates in soil and water and is spread during food handling. The colonization of such harmful microbes has been shown to be 2.1 times greater with glass and 3.0 times greater with stainless steel when compared to copper products. E. coli has shown to remain viable on stainless steel surfaces in excess of four and a half hours, while E. coli is completely dead within 75 minutes of contact with a copper surface.
All facts and figures are taken directly and indirectly from the Copper
Development Association available at www.copper.org/health
Karen,
I'm not sure of the point of your comment quoting the EPA registration for solid copper. First of all, that's solid copper, not copper ions, and they operate via very different mechanisms and vastly different concentrations. See the following for more technical details:
http://aem.asm.org/content/74/4/977.short
http://aem.asm.org/content/76/12/4099.short
Furthermore, a 99.9% (3-log) reduction in 2 hours is considered to be very slow and while fine for surfaces, it is not fast enough for swimming pools and would not pass EPA DIS/TSS-12 which requires a 6-log reduction in 30 seconds for one bacteria and 2 minutes for another -- basically requiring kill times 240-960 times faster than copper solid surfaces. The reason for this is to prevent person-to-person transmission of disease in pools, not just to prevent uncontrolled bacterial growth. Now while I believe that the EPA standard is too stringent, even loosening it to something more reasonable such as 3-log reductions in a few minutes would still not allow solid metal nor metal ions to pass.
* U.S. EPA registration is based on independent laboratory tests showing that, when cleaned regularly, copper, brass and bronze kill greater than 99.9% of the following bacteria within 2 hours of exposure: Methicillin-resistant Staphylococcus aureus (MRSA), Vancomycin-resistant Enterococcus faecalis (VRE), Staphylococcus aureus, Enterobacter aerogenes, Pseudomonas aeruginosa, and E. coli O157:H7.
There are several studies showing a synergistic effect of copper/silver with chlorine for disinfection, mostly increasing chlorine-alone disinfection rates by about a factor of 2, but there are few studies looking at the combination with respect to biofilm. One such study that looked at combinations, but of silver/chlorine not copper/silver/chlorine, is the following:
http://aac.asm.org/content/52/4/1446.full.pdf
where the enhancement of chlorine and silver was small (i.e. the disinfection rate was only a little higher than would be expected by the sum of the two independent disinfection rates -- see Table 1).
These studies are mostly pretty consistent. Planktonic (free-floating) bacteria are killed very quickly by chlorine and much more slowly by copper/silver alone though when used in combination there is a synergistic effect of roughly a factor of 2 in kill times, but given how quickly chlorine kills this isn't a big deal. Such killing of planktonic bacteria significantly reduces the rate of biofilm formation. Biofilms are inhibited from further growth by both, but established biofilms are either not reduced or reduced very slowly by either. The combination of copper/silver with chlorine does not enhance these effects for biofilms by much more than the sum of their individual effects.
I just don't see anything where copper/silver/chlorine is much better than chlorine alone with respect to established biofilms so if biofilms need to be handled, then other means would be needed.
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