ionizers for pools - alternative pool sanitizers utilizing copper and silver ions

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Ionizers are devices that supply a stream of copper and silver ions to the swimming pool water. The copper ions function as an algaecide and the silver ions function as a bactericide. Used properly, the ions are maintained at very low levels, avoiding the possibility of staining or discoloration. Ionization units have copper and silver electrodes and the regulation of the current, between them, helps control the release of the ions. Mineral Sanitizers accomplish a similar end result without the use of electrical circuits, by utilizing an erosion principle. Ionizers and Mineral Sanitizers are not stand alone pool water treatment products, but can reduce the total amount of chemicals required for proper pool water maintenance. Ionization cannot destroy organic buildup and contamination and cannot destroy dead microorganisms and organic debris. The reliance on copper and silver, for sanitizing, requires pool water oxidation and the use of products such as: chlorine, bromine, non-chlorine shock or ozone. While most, if not all, oxidizers can be used with Ionizers, check with the manufacturer before adding chemicals, as to any limitations that might be suggested. The overall water chemistry should be based upon the manufacturer's recommendations. Clicking on the underlined and highlighted "keywords" or "catch phrases," in the archived answers will give you access to additional information on that topic or product. Please refer to the Glossary, if there are terms or phrases that require explanation.

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► Hawaiian Bloom?

Dear Alan, thank you for your informative and very helpful website. Here is my situation: I have a 20,000 pool in Maui, Hawaii. The pool has a copper-silver ionizer system that works fine when conditions are perfect which they usually are (after all, it’s Hawaii!) but I need to supplement when it rains, which rarely happens but this winter has been very unusual with lots of rain. So, I don’t know what I’m doing anymore. What used to work isn’t working and I’m out of my league. First after a big flooding storm the pool became filled with silt run-off. I finally got that cleared up with daily vacuuming and filtering 24 hours a day for 7 days and using a pool clarifier. Then after a day or two of crystal clear water the pool turned green and I got an algae bloom (which I was in denial about and didn’t treat until I couldn’t see the bottom of the pool). After two rounds of copper algaecide and several rounds of shocking with cal hypo, I now have a somewhat cloudy pool that won’t return to crystal clarity. I’ve added the pool clarifier and it’s not responding. It doesn’t seem like algae because the pool is not slimy nor does it smell like algae, however, there is a brown powder-like substance that collects a bit on the steps and I don’t know if it’s leftover silt or maybe mustard algae. The water is in good balance (pH 7.7, alkalinity 85). I am about to put 2 pounds of dichlor in the pool on the recommendation of a pool guy here. He said it will clear up everything. Is this a good idea? Is it better than shocking with cal hypo since it’s not calcium based (which negatively affects the ionizer)? Do I need to put it in at night (pool guy said no)? I have no cyanuric acid or chlorine stabilizer in the pool, since it is usually a non-chlorine pool. He also said to put a 3” chlorine tab in the skimmer to help in a regular basis. Is this actually going to do anything? Or am I just burning up chlorine for no good reason, since I’ve no cyanuric acid in the pool and I don’t want to put any in at the recommendation of the ionizer owners manual? Thanks so much! And if you’re ever in Hawaii, come and visit! Aloha.

Debra G., Maui, Hawaii, 2/17/2004

Until you get the water clear, I suggest that you pretend that you have a chlorine pool. Your ionizer will not solve the problem - chlorine will! There was nothing in your letter about chlorine levels. You need to boost the Free Chlorine level to 5-10 PPM and keep it there until the water clears up. Dichlor will work fine. Day or night - the sooner the better. To help protect the chlorine, it might be a good idea to add cyanuric acid to boost the level to approximately 25 PPM. The brown material is probably silt. Mustard algae is very powdery in appearance and brushes easily. The pH of 7.7 should be lowered to closer to 7.2, as it will help the chlorine work better. As the water improves, add another dose of the clarifier. I suspect that you have a sand filter. If that is the case, you might consider using Zeobrite, a sand filter replacement media. Dead algae can pass right through a sand filter. Zeobrite will remove the dead algae and help restore even better water clarity. Once the pool has returned to optimum condition, you can resume normal operation, which should include shock treatment on a weekly basis, after periods of heavy rainfall, after periods of heavy bather usage or at the first signs of a loss of water quality. Your copper/silver ionizer cannot perform the oxidization function necessary to break down pool wastes and contamination - shock treatment can! The 3" tablet in the skimmer could be of benefit, although I dislike that method of addition. You can minimize the use of chlorine and get better water quality, by adding an ozone generator. I hope that the advice helps and I really would like to drop in for a visit. I haven't been there in 22 years. I'll have to settle for sunny Florida. Aloha.

Sincerely. Alan Schuster, 2/17/2004

Thanks, Alan, for your timely and thorough reply. Yes, I do have a sand filter and will give your recommendations a try. Aloha,

Debra, 2/18/2004

► An Ionizer vs. A Salt Chlorinator?

I'm building a new concrete 26X42 pool and I'm having a little difficulty deciding on the purifier to use. One of my concerns is to eliminate as much as possible any chemicals used (i.e. I hate the smell and feel of chlorine). So I've looked at several chlorine generators and Copper/Silver Ionizers. Some vendors swear by the generators because you don't have to handle chlorine. But, they can't answer my concern that the Chlorine content of the pool is probably no different (i.e. regular Chlorinators). On the other hand, Ionizers claim to use little or no Chlorine. What can you tell me about the relative strengths, beyond trivialities, between generators and Ionizers? Any recommendations are appreciated.

Mike S., 8/22/2003

Mike S., 5/13/2004

With an Ionizer you will still have to add chlorine, bromine or non-chlorine shock on a regular basis. Otherwise, organic byproducts will buildup to problem levels. The use of chlorine or bromine will act as a backup sanitizer and help assure better water quality. The ionization unit will reduce the use of chemical sanitizing products - how much less will depend on your particular usage pattern. The POOL FROG combines mineral sanitizer and salt chlorine generator technologies and allows the chlorine requirements to be reduced to about 1/2 of the normal level. The overall pool chemistry must still be maintained, as with any pool. Your concern about chlorine should be eliminated. Under normal conditions, it is chloramines that prove odorous and irritating. With a salt chlorination system, all the water passing through the cell will be free of odorous and irritating chloramines and there should be much less of a sensation of chlorine being in the pool. My own long-term, experience bears this out. It is the chloramines - not the chlorine that are smelled. There are no chlorine containers to handle or store! As with any chlorine pool, you will have to maintain all of the other water chemistry parameters. Test the salt level, periodically to assure that the amount is within the proper range. Good luck with your decision. I hope that I have been helpful.

Sincerely. Alan Schuster, 5/13/2004

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► Ionization 101?

Is there any research that proves that ionization or mineral purifiers are effective pool treatment options, with comparison to chlorine or bromine treated pools?

Toby W., Christchurch, New Zealand, 5/11/2004

While I don't have any research findings on ionization, I'm sure that such material exists. Ionization units have been around for at least 30 years. The theory is sound: silver provides bacterial sanitizing and copper provides algaecidal action. You still have to maintain the overall water chemistry. It will reduce chemical consumption, but will not eliminate the need for shock treatment for oxidation of wastes, debris and byproducts. If you want to completely eliminate the need to handle all chlorine and shock treatments, you should think in terms of a salt chlorinator. If an ionization unit is used with a salt chlorine generator, it will allow the free chlorine results to be maintain at a much lower 0.4 PPM and still have optimum results. This lower chlorine requirement will extend the life of the salt cell. I hope that I have been of some assistance.

Sincerely. Alan Schuster, 5/11/2004

► Sequester Or Not To Sequester?

We have many customers that are switching to ozone, ionization or mineral cartridges. We live in an area that has high mineral content, and to solve this issue we have had our customers use heavy amounts of a sequestering agent. This has solved many of the staining and discoloration issues. My question to you is will the use of a sequestering agent inhibit the effects of a mineral cartridge using silver or zinc? And if so what do you suggest to eliminate minerals while still using the mineral cartridges if the customer doesn't have a water softener? Sincerely.

Justin N., 10/31/2003

Chemicals used to treat calcium and other metals can interfere with ionizers and some mineral sanitizers - especially those that rely on copper and/or zinc. The FROG Mineral Sanitizer utilizes silver ions and metal treatments should not present a problem. While not all sequestering or chelating agents may cause problems, I can't tell you which will or won't. I hope that I have been helpful.

Sincerely. Alan Schuster, 10/31/2003

► A Case For Ionization?

We just bought a house with an indoor pool. It is a bromine system now. The problem is I am very sensitive to bromine and chlorine and I break out in a really bad skin rash, after swimming that takes weeks to go away. I don't have the problem when I go into a lake or pond. The ocean tends to dry out my skin, but doesn't give me a rash. If we switch to ionization does that end the problem? I see that there are a number of manufacturers - how do I know which product is better? Some have cartridges to be replaced-are there electrodes that need to be replaced? By how much will I reduce the amount of bromine needed in the pool? It's a 16x32 foot pool 8-9 ft deep. Since we are going to be using the pool a lot, through the year, what would be the better system? I know I have asked too many questions for one day, sorry. But, we are very excited to have the pool and I can't go in yet- please help.

Jonathon R., 4/25/2005

You have made a convincing case for avoiding chlorine and bromine. However, it is not that simple! You can sanitize the pool without chlorine or bromine, by using a mineral sanitizer or an ionization unit. However, you must add oxidizers to destroy organic wastes and contamination. For this purpose chlorine or bromine are frequently used, but in your case this would not make sense. That leaves one other product: non-chlorine shock. Still there is a complication. Unless you drain the pool and replace the water, adding non-chlorine shock to the pool, will convert the bromides (from bromine use) to active bromine sanitizer. And, if you were to drain the pool, the addition of non-chlorine shock might still convert into chlorine, based on the expected presence of some sodium chloride. Using an ionizer or a mineral sanitizer and non-chlorine shock could still be worth considering, as there would be less odor and less of a chlorine or bromine presence. Something better would be the combination of ozone and ionization. An ozone generator can help eliminate all of the wastes. Ionization units use electrode plates to add silver and copper ions to the pool, at controllable rates. Mineral sanitizers use a less controllable erosion principle and a mineral cartridge, to add metallic ions. TechnoPure Ionization-Oxidation units features a hybrid approach, that uses copper and zinc ions for sanitizing, while producing active forms of oxygen to destroy organic wastes and byproducts. It greatly reduces the chemical presence, by utilizing technology developed by NASA for use in the Apollo space program. If you want a modern approach to sanitizing, this could be it! For more information go to: www.technopure.com I hope that this information will help you make the best decision. Please let me know how things work out!

Sincerely. Alan Schuster, 4/26/2005

► Ionization And Chlorine?

We have a 120,000 litre ionised pool with spa to which we add 5L of liquid chlorine to weekly in summer and about 3L in winter. The pool is always crystal clear. I have recently started using a company to do the pool maintenance for me and they keep telling me the chlorine levels are too low. Should an ionised pool have a specific chlorine reading? The pH level is always too high after 1 week (usually needs about 1 cup acid weekly) - is this normal or is there a better product to use than liquid chlorine to maintain a better pH level? Sorry, being Australian, I can only work with metric!

Wendy, Australia, 9/2/2007

Liquid chlorine is a good choice. You should maintain the same free and total chlorine levels as any other chlorine-sanitized pool/spa. Even though you have an ionizer, the levels should be the same. However, the presence of an ionizer should allow you to use less chlorine to maintain any given level. Liquid chlorine has a high pH and regular additions of acid are required. Adding an ozone generator will reduce the amount of chlorine used and make pH control much less of an issue. I hope that this information is helpful.

Alan Schuster, 9/3/2007

► Ionization-Oxidation?

Dear Alan, your fame spreads far and wide! Another couple of questions from the other side of the pond (U.K.) I am considering fitting an ioniser, several manufacturers out there, some use copper electrodes, some copper and silver, some use copper, silver and zinc. from my own studies of bacterial research via the web it appears that there is a synergy between copper and silver which provides a kill rate at 4ppm which can only be matched by copper alone at 8ppm therefore am I correct that the life of the electrodes (copper&silver) will be longer due to the amount of ions required and also the electricity required will be less saving the planet a bit more not too mention that staining should be less? Second question, You do not seem to mention that some manufacturers include a second pair of electrodes (titanium or platinum) that are used to provide oxygen to burn up those impurities normally carried out via chlorine, thus eliminating chlorine completely. What are your thoughts? I have also found a German company that has made diamond surfaced plates that produce 100% more oxygen than platinum plates. Kind regards.

John W., U.K., 4/10/2007

I will always have fond memories of the UK and the pool business, having attended a trade show in Brighton, many years ago. Ionizers (forgive the spelling) sanitize by releasing metallic ions: copper, silver and zinc. As far as concentration is concerned, 4 or 8 PPM, is far too high, as that would likely result in staining and discoloration problems. Levels in the tenths of a PPM would be more appropriate, in a swimming pool. While an ionizer helps sanitize the water, it is not a complete system. Oxidation will still be required. Towards that end, an Ionization-Oxidation device is more of a complete sanitizer. These devices can have copper and zinc electrodes and electrodes for producing various forms of active oxygen. Apart from thinking the plates are titanium with a Platinum or Ruthenium coating, I have no knowledge of a diamond coating. To make an Ionization-Oxidation unit much more of a complete sanitizer, you could use it with chlorine or bromine, at very low levels. It can be challenging to totally eliminate chlorine, as its presence on a persistent basis provides both sanitizing and oxidizing and it might be required, occasionally, if the bather loads are high or conditions warrant. The maintenance of a minimal level of chlorine or bromine, helps to confirm that the sanitizing and oxidizing needs are being met. For those that want to totally eliminate chlorine, Ionization-Oxidation could be a route. Adding high efficiency filtration, The Circulator for improved circulation or a UV sanitizer will make success more likely. If you want to minimize the use of chlorine, Ionization-Oxidation will surely accomplish that and more. I hope that this information proves useful.

Sincerely. Alan Schuster, 4/10/2007

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► How Do Ionizers Work?

Could you explain how an Ionizer works? Simply, if possible. Thank you very much.

Tom M., Ukiah, CA, 12/2/2003

Most Ionizers work on the principle of adding a low level of silver and copper ions to the water. Ions are the electrically charged soluble form of these metals. The copper ions function as an algaecide. The silver ions function as a bactericide. At these low levels, staining and precipitation should be eliminated. The Ionization unit contains a silver and copper electrode and the regulation, of the current between these electrodes, will control the amount of copper and silver ions released into the pool water. The device is plumbed in line and operates with the same cycle as the filter. A Mineral Sanitizer is another type of device, utilizing metallic ions and minerals, instead of the electrodes. In either, case the sanitizing principle is similar. In addition to the copper/silver Ionization, there must be oxidation. For this purpose chlorine or a non-chlorine shock are usually used, in order to destroy organic contamination and build up and to destroy dead algae and debris. An ozone generator can accomplish the oxidation, while reducing the chemical usage. The overall water chemistry must be maintained for bather comfort, water quality and to protect the pool surfaces and equipment. These products will not necessarily allow you to eliminate chlorine completely, but will allow you to get satisfactory results, while maintaining a lower level. I hope that I have been of assistance.

Sincerely. Alan Schuster, 12/2/2003

► Floating Ionizer?

You've given me valuable information before about salt water chlorinators. I've just come across a floating, solar-powered ionizer. How do you rate this product compared with a salt water chlorinator?

Kevin R., United Kingdom, 4/5/2005

This product does not produce chlorine. It is an ionizer and probably releases copper and silver ions into the pool water, when there is sunlight to power the solar cells. Ionizers do not have to work 24/7 and this type of unit might produce enough sanitizing ions, even if there are cloudy periods. It is however, not a complete stand alone product. It must be used with chlorine or other oxidizers, in order to destroy wastes and to act as a proper sanitizer. A salt chlorine generator is a much better choice, as it can act as a complete, stand alone, sanitizer. I hope that I have explained the difference.

Sincerely. Alan Schuster, 4/5/2005

► Black Patches?

Hello, my name is Jan and I live in Brisbane Australia which has a sub tropical climate. I have been reading the interesting information on your web site, particularly with regard to Vitamin C and pH reducer powder for clearing of stains. My problem is this. I have a 50,000 litre in-ground copper ionised pool ( 2 sacrificial copper anodes) with vinyl liner, which is now approx. 7 years old. Recently light black patches of staining have appeared on the floor of the pool - less noticeable when the pool is in full sunlight but once the shadows come over it, they are quite obvious. I keep the pH at 7.4 - 7.6 and the water is very sparkling and clear. What would you suggest I use to get rid of the staining - could the abovementioned treatments be of help to me? I get a bit despondent with pool shop people as they all seem to give such differing opinions on what one should do, so mostly I look after it myself now and I have to say it appears to be in very good shape - apart from the staining of course!! Thanks you very much in anticipation of your help. Regards.

Jan B., Brisbane, Australia, 4/15/2005

Trying to apply vitamin C and pH reducer granules to the blackened areas is worth trying. If the cause of the staining is copper, especially likely in the presence of high calcium hardness levels, it could be successful. And if that is the case, I would pay more attention to the copper level and try and keep the pH at 7.2-7.4. However, there are other possible causes for such a problem: algae, leaf stains and a fungus growing on the reverse side of the liner. For the latter, there is little to be done and it will not respond to chemicals being added to the pool water. Shock treatment can help deal with algae and leaf stains. People using ionizers usually try to avoid chlorine, but sometimes it is necessary to solve a problem. An ozonator is a practical way to oxidize the wastes and reduce the chemicals being added for oxidation. Black algae sometimes requires a regimen. Browse through the archives on that subject, for additional insight. Good luck and I hope that this information will help.

Sincerely. Alan Schuster, 4/15/2005

► Too Much Copper?

Thanks great website. I need your help I have a pool guy coming to clean my pool every week suddenly the pool sides are turning blue and under the pump where it was leaking it is purple this has been going on for a week now. He says everything is fine as far as the chemicals are concerned. the pool is in ground 20x40 the water looks clear but the sides and the baskets are turning a sky blue. Can you help? Also I also have a copper ionizer, as well .

Joe K., 5/11/2006

I am not sure what kind of ionizer you have, but I suspect that your problem is too much copper. It could be set too high. I suggest that you have the water tested for copper and manganese. Treatment may be necessary and that can present a problem with an ionization unit. The stains may require using ascorbic or oxalic acid. Try placing a few vitamin C tablets on a stained area. If it works, the pool should be treated. You may have to lower the pH of the pool to 6.0, discharge all of the chlorine and add a few pounds of the oxalic or ascorbic acids. I hope that this information proves helpful.

Sincerely. Alan Schuster, 5/11/2006

You were right it has a high content of copper. It is recommended to unhook the ionizer, which uses copper electrodes and empty half the water and then treat. Would that be your recommendations? Thanks so much. I will recommend this site to all my pool buddies

Joe K., 5/12/2006

That would lower the copper content and make more staining less likely, but you still have to deal with the stains. In the future, operate the ionizer at a lower setting.

Sincerely. Alan Schuster, 5/12/2006

► The Shocking Story?

I have been using an Ionizer on my pool for several years. I was instructed to use a non-chlorine shock, on a regular basis. I understand the need to shock the water because the Ionizer will not destroy organics and dead algae. I am wondering if I can use a chlorine shock, instead of the non-chlorine shock? I like the Ionizer, but maybe chlorine shock would be more convenient and cheaper? Thanks.

Bill W, 6/4/2004

Most people, buying a Ionizer, do so to avoid chlorine completely. The combination of an Ionizer and non-chlorine shock does just that. So far as I know, ionization units can be used with chlorine or non-chlorine shock or, better still, an ozone generator. The presence of an ionizer will allow you to maintain ideal conditions with less chlorine. I know that certain mineral sanitizer products, ones that work on a erosion principle, may not be able to be used in bromine-treated pool water, but can be used with chlorine. These products will not necessarily allow you to eliminate chlorine completely, but will allow you to get satisfactory results, while maintaining a lower level. In any event, I suggest that you follow the manufacturer's recommendations, so as to assure proper functionality and product life. I hope this information proves helpful.

Sincerely. Alan Schuster, 6/4/2004

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