Natural Pools

There is an emerging trend of natural pools in Australia. A natural pool is a pool that is free of chemicals and relies on an artificial fresh water ecosystem to maintain its water condition.The following is extracted from the BioNova website:"At the heart of the BioNova natural water system is the biological filter, this attractive water garden is where micro organism’s, microbes and water plants ensure effective and continuous cleaning of the water. The root system of the water plants in the regeneration zone absorb nutrients from the water that micro organism’s release during the decomposition of germs and organic substances.The water flowing through reeds and roots is biologically and mechanically purified in the underlaying substrate filter layers before it is returned to the swimming zone as crystal clear mineral rich living water."What is everyone's views on Natural Pools. Is there much maintenance involved? Are there health risks? Is it the future of swimming pools?

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  • Richard, 

    Fantastic information!!


    Richard A. Falk said:

    Mitch,

     

    How can your customer explain the fact that algae grew so readily as soon as you stopped adding chlorine to the pool in spite of this wonderful Grander system that presumably keeps the water so pure?  If you want to have something as "green" as possible to help prevent algae growth, use a phosphate remover.  Your customer seems to be opposed to adding anything, but removing things is probably OK.  Of course, if you use an excess of phosphate remover you'll have some lanthanum ions leftover that hopefully he won't freak out about and, of course, there will be some leftover chloride ions.

     

    As David points out, using ozone is another non-halogen approach and it provides both disinfection and oxidation, though the disinfection is primarily in the circulation path.  The tricky balance has been how to provide enough bulk-water disinfection without having too much outgassing of ozone.  This is why it is not used alone in any commercial/public pool (i.e. it is always used with an EPA-approved disinfectant such as chlorine).  If an ORP of 700 mV is being measured away from the returns in the bulk pool water, then it would be interesting to see the measured amount of ozone in the water and whether the amount in air above the water exceed the EPA ozone air quality standard.  In most ozone systems used in pools the contact tanks are designed to outgas and remove most of the ozone before reintroduction back into the pool in order to lower the ozone levels swimmers would breathe.

     

    Using chlorine at night (no CYA needed if it's only used at night and a very low amount of chlorine can be used -- 0.2 ppm FC, for example) is an interesting hybrid approach assuming the chlorine isn't consumed before it reaches areas of the pool where biofilms might otherwise form.  ORP isn't an absolute level in spite of what manufacturers say -- it varies by sensor.  For example, 0.2 ppm FC with no CYA at a pH of 7.5 and 80ºF Chemtrol would report 716 mV while Oakton would report 681 mV while Aquarius would report 627 mV, etc.  I write about some of these inconsistencies with ORP in this post.

  • Mitch,

     

    How can your customer explain the fact that algae grew so readily as soon as you stopped adding chlorine to the pool in spite of this wonderful Grander system that presumably keeps the water so pure?  If you want to have something as "green" as possible to help prevent algae growth, use a phosphate remover.  Your customer seems to be opposed to adding anything, but removing things is probably OK.  Of course, if you use an excess of phosphate remover you'll have some lanthanum ions leftover that hopefully he won't freak out about and, of course, there will be some leftover chloride ions.

     

    As David points out, using ozone is another non-halogen approach and it provides both disinfection and oxidation, though the disinfection is primarily in the circulation path.  The tricky balance has been how to provide enough bulk-water disinfection without having too much outgassing of ozone.  This is why it is not used alone in any commercial/public pool (i.e. it is always used with an EPA-approved disinfectant such as chlorine).  If an ORP of 700 mV is being measured away from the returns in the bulk pool water, then it would be interesting to see the measured amount of ozone in the water and whether the amount in air above the water exceed the EPA ozone air quality standard.  In most ozone systems used in pools the contact tanks are designed to outgas and remove most of the ozone before reintroduction back into the pool in order to lower the ozone levels swimmers would breathe.

     

    Using chlorine at night (no CYA needed if it's only used at night and a very low amount of chlorine can be used -- 0.2 ppm FC, for example) is an interesting hybrid approach assuming the chlorine isn't consumed before it reaches areas of the pool where biofilms might otherwise form.  ORP isn't an absolute level in spite of what manufacturers say -- it varies by sensor.  For example, 0.2 ppm FC with no CYA at a pH of 7.5 and 80ºF Chemtrol would report 716 mV while Oakton would report 681 mV while Aquarius would report 627 mV, etc.  I write about some of these inconsistencies with ORP in this post.

  • The Bio-Nova system is amazing, and I truly believe it will catch on eventually her in the US, I'm just not sure the public is quite ready to embrace it with the state of the current economy.

     

    Since you have a pretty traditional pool currently, and aren't in a place to transform it into a NSP (BioNova) type pool, have you considered installing a large Corona Discharge Ozone system.

     

    We have been installing these for a little over a year now, and the overall results have been fantastic.

     

    We install them with full pH/ORP controllers as well.  We run the water unstabalized, feed a little chlorine in the middle of the night, and then let the Ozone take over early in the morning.  We always use large contact tanks (120 gallon on residential pools) with all our systems.  We currently spec CD10 systems (4 grams of Ozone per hour) on our residential spas, and CD12 systems (8 grams per hour) on our residential pools. 

     

    The clients are thrilled with the results, and the water quality is amazing... We are maintaining an ORP well above 700 on a recent pool, and the client swims every day.

     

    The important thing to look at is how much ozone is generated by the system... many of the small $1,200 systems out there only generate 1 gram or less per hour of ozone, and they are not nearly as effective at disinfecting pools.

     

    Just a thought.

  • Thanks for your input.  He wanted to do it - he understands we do not support it and are not responsible for it.  He views it as an experiment and is willing to pay for us to monitor and find the best way to put it to use.  He wants the pool as "fresh" as possible - freaked out when I added salt.  He wants the least amount of chemicals possible.  Last week he did ask us to turn the Chlorine Generator off to see how Grander would do on its own - I had algae growth the next day, he understood I then needed to shock and add algaecide - I also turned the generator back on, but I'm running low on salt, he's not going to be into adding more salt.  Now I also need to have the stabilizer discussion with him because it's not holding a residual.  BTW - This is the Einstein quote he used in an email regarding Grander, "Great spirits have always encountered violent opposition from mediocre minds."  He's a VERY smart guy - he's done his research, he believes in it - I want to, but I can't.  Not yet...
  • Our predecessors swam in lakes, streams, ponds and the oceans of the world long before pools and spas were developed.  You can still do so, but, it is defiantly not as sanitary as a swimming pool.  Thanks again to Richard for the links to call out the hooey some manufacturer's spew.
  • As described in this link, Grander technology is a bunch of pseudo-science bunk.  It isn't even worth discussing, really, but you can read more about it in this link (unfortunately, many links have gone dead over time -- this one regarding the lawsuit in New Zealand is current).  There are no laws requiring a residential pool owner to properly disinfect their pool.  There are FIFRA rules for EPA pesticides regarding claims and dosage instructions on labels and documentation, but homeowners can swim in cesspools if they want to.  This is similar to how there are strict regulations regarding sanitation in commercial kitchens, but if you want to leave a chicken out on a counter in the sun all day in your home and then prepare vegetables in its juices left on the counter, the government isn't going to stop you, fine you, or anything else.  You should refuse to install the Grander system since you do not want to be liable -- either that or make sure you get the customer to sign a waiver completely absolving you of all responsibility.  It's one thing for a homeowner to do this on his own, but quite another to have a professional involved.

     

    As for NSPs, they obviously don't do anything to prevent person-to-person transmission of disease since there is no fast-acting bulk disinfectant in them.  There are many incidents of people getting sick in natural waters, some even dying from them (see this link though that is a rare occurrence; far more common are diarrhea illness from E.coli, norovirus, Shigella, Giardia and Crypto), but there is a HUGE difference between having a large body of water or one with a very high flow rate (such as fed from a fresh river or stream) vs. having a smaller relatively stagnant body of water.  The amount of fecal and other bacteria shed from the body is large so its removal is limited to the rate at which it gets "filtered" through the natural systems, be it sphagnum moss or other plants.  Most of these systems are banking on the fact that getting sick from even untreated water is a statistical probability low enough to not have too many incidents.

     

    If someone really wants to be halogen-free but have protection against at least some pathogens, then there is Baquacil/biguanide/PHMB with its associated costs and issues or there is copper/silver (NOT copper-only since copper at pool concentrations does not do anything against fecal bacteria) with its associated risk of staining.  Just note that though these alternatives kill bacteria, copper/silver does not kill viruses and the kill rates for bacteria are slow, though for residential pools are probably reasonable (see this post for more technical details) since they are generally fast enough to prevent uncontrolled bacterial growth though not fast enough to prevent person-to-person transmission.

     

    As far as any "emerging trend" in Australia is concerned, given this information from the APVMA I do not believe that natural pools will be used in ANY commercial/public pool since they have even cracked down on copper/silver ionizers in terms of their pathogen kill claims.  Australia, like the U.S. and many countries in Europe, requires the use of a bulk water fast-acting disinfectant.  In the U.S., the EPA has approved chlorine, bromine and Baquacil/biguanide/PHMB.  For hot tubs only, Nature2 with MPS is also approved.  In Australia, there is also hydrogen peroxide approved in limited situations (mostly for spas).  In Europe, countries following German DIN 19643 use chlorine though at levels of 0.3 to 0.6 ppm FC with no CYA and with various forms of coagulation/circulation/filtration.  Again, in all of these countries there is a big difference between commercial/public pools with their higher bather loads and greater risk of liability where one sick person can infect dozens if not hundreds compared to private pools where personal responsibility is assumed and the risks are lower.

  • Does anybody dealing with NSP's have any experience or knowledge about Grander Water Technology?

     

    http://usa.grander.biz/en/products/grander-water-treatment-units

     

    I believe it was originated in Austria.  The way I understand it is that the units contain clean fresh water from the mountains of Austria and some how, by "information transfer," the unit teaches the water that passes through it to revitalize itself.  This is a serious topic which has been brought to my attention.  A client has asked us to install this system and turn off the chlorine generator.  I'm hesitant and concerned.  We have a small immersion unit in one skimmer and a larger immersion unit in a cartridge-less cartridge filter.   

  • I am so glad to see you folks talking about Natural Swimming Pools!

    We have just learned about poolgeniusnetwork and joined. We are BioNova Natural Pools USA. Bryan Goh is referencing our Australian partner, Peter Watson's website. Peter is a passionate guy about Natural Swimming Pools and started BioNova Australia about 3 years now. We started BioNova USA about a year ago and have been working furiously to gear up our marketing here in the US.

    Mike Logsden at Land Design Texas just climbed on board with us and he has a really great NSP project in the Texas Hill Country.

    To address what Karen is reporting about builders who think these NSP's would be a hard sell, we agree that they would be a hard sell if you're trying to convince somebody who is skeptical that they should buy one! These pools are NOT for everybody! So if clients are looking for crystal clear, algae-free, antiseptically clean water, they should not be considering an NSP - they should build a chemical pool.

    These watershapes got their start in Austria about 25 years ago. In German, they are generally called either Schwimmteich or Badeteich, which translates into English as "swimming pond" or "bathing pond". Unfortunately, I think, they have been called Natural Swimming Pools in English. I prefer to call them NSP's because it obscures the misleading term Natural (they are not actually natural - they are constructed) and Pool (they are more like ponds than pools). But, I do agree with the Swimming part of the term!

    We think that this is a niche market - but it definitely is a market. Clients who would like a "swimmable pond" in their yard, who aren't afraid of a little algae and understand that an NSP is a natural ecosystem - clients who aren't afraid to swim in a pond or a lake, clients who appreciate a water garden - these are the folks for whom an NSP is not a hard sell. They already want one.

    We've been to Europe 5 times in the last year and a half, researching NSP's, attending seminars and going through the BioNova training program, visiting installations and talking with other BioNova partners. We've seen lots of these pools - we think that they are beautiful and that they make a lot of sense. We don't think that they are the future of swimming pools - but we think that they are a market niche that has huge potential.

    By the way, our background is that we own Rin Robyn Pools, a traditional pool design/build company located in NJ. I have personally been working in the pool business over 35 years - so I've been around the block a couple of times.

    We'd be happy to share information about NSP's - and we'd appreciate keeping this discussion going!
  • Funny you should mention this - I chat with quite a few pool builders every day and I have been asking about natural pools in their markets as I recently read an article about building them during a research project. I live on a small spring-fed lake where we used to swim during the summer - until we got a pool! so the natural environment is not too foreign to me. The builders I've talked to however, seem to think it would be a hard sell in their markets. - Karen Thhttp://www.motherearthnews.com/Do-It-Yourself/2002-08-01/Natural-Swimming-Pools.aspx
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