Can I Use Salt As Sanitizer Instead of Chlorine?

[BigTallGuy]

Catfish, I understand your request for information, however, I want you to take a step back and consider the following.

I honestly believe Ben, the Administrator, is trying to help you with your research by sharing information regarding the safety and sanitation of your pool project. If you really want to look at the big picture, it is not only about “wiping my butt before I go for a swim” or making sure everyone visits the bathroom before diving in. It is about pool sanitation with regards to not only human wastes, but animal wastes (dogs, cats, birds flying overhead etc.) and insects too. I clean flies, bees, grasshoppers, etc. out of my skimmer constantly, and who knows what they bring to the pool. I believe Chem-Geeek has provided enough information to prove that Salt alone, in most cases, is not a sanitizer in swimming pools.

This Forum is comprised of a lot of good people that get nothing more than the satisfaction of helping people across the US and Canada with their swimming pool problems. We get a full array of people seeking help and information, everything from rich people with huge swimming pools to single Moms with small above ground pools. Our charter is to provide sound advice, to the best of our ability, for the safety and affordability to all. We would be remiss if we didn’t advise you (or anyone else) of what we have learned or what has been proven.

Unfortunately, a website like this also attracts a boat load of spammers as well as “Know-it-alls” that are mostly mouth and very little ear. If you choose to continue to visit this Forum, you will learn that there is no corporate sponsor or commercial enterprise subsidizing this Forum. In reality, we primarily promote the BBB method which fundamentally promotes pool care with grocery store items that basically undermines the profits of all of the Big Pool Chemical Companies as well as a slew of Pool Supply Stores. Pool cleanliness and sanitation is paramount with the BBB method, simply put, if it didn’t work, what good is it? The BBB method has withstood the test of time because it works.

We have seen the gamut of “Trouble Free” and “All Natural” claims, and virtually all fall short. There is no Known “Free Lunch” when it comes to swimming pools and their care, including performing simple tests. If there was a secret or magic pill with regards to swimming pool setups, I’m sure the people on this Forum would know about it, and in all probability you’d read about it first, right here.

In the end, it is your project and idea. Your safety and health, and that of your family, friends, and guests, that would potentially swim in your pool is in your hands.

[catfish]

I think the disconnect here is the interpretation of "there is no free lunch" as "you must pay $0.99 for a McDonald's double cheeseburger; everything else is crap." The inertia of the status quo should not be elevated to a dogmatic religion. Everything in life is a tradeoff.

So let me begin by saying I was not aware of virus resistance to high salinity, and I think UV light shows great promise, being ultimately (though maybe not in the currently available implementations) low maintenance, low cost, low side effect and highly effective. That said...

I believe Chem-Geeek has provided enough information to prove that Salt alone, in most cases, is not a sanitizer in swimming pools.

Nonsense. I was going to invent a hypothetical pathogen that was resistant to chlorine just to make my point about life being mostly about tradeoffs, not right ways vs. wrong ways. But chem geek has helpfully provided me with a real example: Cryptosporidium parvum.

He made some good proof-of-concept points. Extrapolating that out to concrete, unshakable conclusions that cause administrators of large forums to ban or obscure discussion of anything not toeing the status quo is annoying at best. Health statistics are rarely as cut and dry as you think. Example: Everyone (especially politicians) still won't shut up about how much money smokers are costing us in healthcare. *Wrong*. They actually save society quite a bit of money by dying an average 7 years earlier, even taking into account the cost of their lung/cancer treatments. And that's without even considering the extra sin taxes they pay.

A better example: condoms. Fantastic efficacy on paper, mediocre performance in real life because people make mistakes or just don't care to use them right. When deciding how best to fight AIDS in Africa, which statistic is more important? The one that reflects actual reality, of course. Similarly, any comparison of chlorine to salt water should in the context of infectious disease should use real world figures, taking into account everyone who has a screwed up pool chemistry and doesn't know/care.

"Look at the CDC Surveillance Summaries for Waterborne Disease and Outbreaks..."

I skimmed the reports and, though it's entirely possible I am missing something important (sadly I do have a life), it appears they are relying on voluntary self-reporting of *mass* outbreaks from public health agencies. In other words, they are useless. Even if small-scale (personal, not public) chlorinated pools were ten times more infectious than the ocean on a per-person per-hour basis, you still wouldn't see any mention of it on those reports. There *might* be an implicit approval of public pool chlorination in there, but there is nothing I could see applicable to a smaller saltwater body mostly sheltered (see below) from animals and pollution/sewage discharges, and used by a small group of people.

"do you open your eyes underwater in the ocean?

Nope. Nor in pools. Both make my eyes sting.

"metal corrosion issues"

Then don't put metal stuff in the pool? Certainly, any fool that dumps huge quantities of salt in their existing, conventional pool and flips on the pump gets what he deserves.

"and killing of plant life and contamination of waste water treatment plants for inland locations"

Most pools aren't very far inland for the simple reason that most of the population lives pretty close to the ocean. (Go find nighttime pictures of the earth if you don't believe me.) Salt is already legal to buy, and in large quantities. I'm aware that, in the course of human events, the government may need to enact laws to keep stupid people from doing very stupid things, but this is neither here nor there. If you must harp on it, just keep in mind that the stupidity cuts both ways--most people cannot seem to keep their pool chemicals anywhere near where they should be.

"A critical point that is being missed, however, is the volume of water.

I already covered that. And it's not volume, it's contaminant/volume.

The problem with citing marine statistics is that a saltwater pool or pond would not be exposed to the same marine organisms. Comparing sewage contamination is even trickier.

As I said, I'm halfway-seriously thinking about something much bigger, but let's assume not. I don't know what you yankees do, but a regular sized inground pool is frequently/usually enclosed by screen down here... mosquitoes and pine needles are way too annoying. And a good screen will cut out almost all of the animal contamination issues, leaving behind perhaps a few small bugs. So does that leaves mainly person-to-person transmission, or are smallish insects and arachnids enough to introduce harmful pathogens? Person to person transmission can indeed be significant, but it entirely depends on what you, your family, and your guests' habits are.

My conjecture, assuming everyone wipes their bottoms: if you forget to wash your hands before eating (or before touching your eyes, mouth or nose) as little as 5% of the time, and your guests/family do the same, your fecal/oral transmission rates aren't going to be significantly affected by a little saltwater dip. And how quickly do all of those fecal-oral organisms die in chlorinated water anyway? Right away? I bet not... the real statistics aren't about killing vs. not killing, it's time-to-kill xx%, which probably isn't hugely relevant if you're swimming a few feet from the infected person.

Yes, I play fast and loose with conjecture for the simple reason that millions of people already take much worse risks, and it definitely unclear whether the current solution is ideal. I appreciate the factual responses, but the attitude and conclusions are sickening. You know, we are still stuck using gasoline engines that run on a very limited set of fuels, have crap mileage and crap fuel density, and simply wear out in under 200k miles because "duuuur, diesel is expensive!" Which, after a little bit of research and back of the envelope calculations, is clearly the opposite of true. Same attitude here, except the figures have yet to be shown, but that clearly doesn't stop the resident armchair biologists.

[PoolDoc]

Catfish, I have to thank you.

I've been wanting -- for purposes that have nothing at all to do with the PoolForum -- to have a great, real-world example of contemporary post-modern reasoning: ie, 'there is nothing that's completely true, and I'm absolutely sure of that!'.

My older son had collected several examples from some of his professors several years back, but that was second hand. Yours is first hand, 'in your own words' so to speak and not enveloped in an academic context. I especially liked the way that you criticized some of the data sources for incompleteness, or for failing to screen data-selection errors (with some validity) and then turned around and noted (with exceptional validity) that

Yes, I play fast and loose with conjecture . . .

Who could argue with you, on that last point?

You are articulate, bright, and irrational -- a truly potent mix, and one that has become increasingly common as non-scientific higher education has abandoned rationality, except as a garnish or as a ploy in debate.

As for specific rebuttal of some of your claims, that will be hard to do coherently, since your claims and ideas are so scattered and directionless, but again, for the sake of the lurkers and Google, we'll try to take it up later when things are less busy.

I assume there's no functional urgency: it appears that don't have a pool problem, or even a pool, at present.

Gratefully yours,

PoolDoc

[catfish]

Saying that the world is full of tradeoffs and saying that there is nothing completely true are two very different things. For instance, I never said and in fact disagree with the latter.

I will never forgive the postmodernists and naturalistic junkies, because they've basically sabotaged the ability to have a discussion about the relevance of empirical evidence, let alone discussing reasonable courses of action in the absence of it (hint: a diversity of approaches will actually provide you with the missing data.) It's funny, though, I bet if I mentioned the data linking chlorination to bladder cancer you would be quick to dispute it, perhaps even using analogies similar to the ones I resorted to. And of course, with the quote you use to mock my approach you conveniently discard the justification with ellipses.

So would I be irrational to swim in the local pond? Are all of the kids and parents irrational for doing so? How do you think we should best address such irrationality?

[catfish]

Also, ftw, I have a degree in actuarial science and am well on my way to passing my second exam.

[ random fluff deleted - PoolDoc ]

And maybe all of that probably falls outside the expected scope of a forum like this, but...

well, it shouldn't.

[PoolDoc]

And maybe all of that probably falls outside the expected scope of a forum like this, but...

well, it shouldn't.

My forum; my choice. Discussion of gastritis and the etiology of duodenal ulcers is not really germane here. If you want to start a swimming pool forum, where such things are considered OT, be my guest!

[chem geek]

catfish,

I have to admit that I am totally lost with your reasoning. Yes, I understand tradeoffs, but when you initially said that high salt levels should kill off pathogens and then I provided information that showed that many pathogens including fecal bacteria can survive (and some thrive) in salt water, you seem to ignore that. Chlorine kills most pathogens very quickly and the most notable exception (mostly in commercial/public pools) is Cryptosporidium parvum. However, I completely am missing your logic of how that one pathogen justifies throwing out chlorine and replacing it with salt water. Crypto is planned to get handled, albeit slowly, via UV or ozone via the circulation system for future commercial/public pools in the U.S. Also, Crypto is usually not an issue in residential pools because it is only introduced into water from a sick individual (usually with diarrhea).

UV or ozone only kill pathogens that get circulated. They do absolutely nothing to pathogens on pool surfaces (bacteria tend to grow best on surfaces and form biofilms that are harder to kill so need to be killed quickly before that happens) and they also do not kill quickly since turnover times are generally measured in hours and it takes 5 turnovers to reach 99.3% of the water under ideal mixing conditions (only 63% of the water goes through the system for each turnover). You have to have a bulk water disinfectant of some sort to prevent both uncontrolled bacterial growth and to prevent person-to-person transmission of disease. Salt water alone doesn't allow for that. If it did, there would be no microscopic life in the ocean and I've already linked to human pathogens that survive in salt water.

As for the surveillance reports I referred to, they were by necessity for commercial/public pools and only for outbreaks since that is all that gets reported. But at least that's some sort of data compared to what you are providing (i.e. nothing at all). Residential pools tend to be safer due to the lower bather-loads and not having sick strangers visit the pool on a regular basis. However, there aren't good statistics about that safety since as you point out people who get sick from their pools will just, at most, go to their doctor and it won't likely get reported to any central government agency (and the doctor probably wouldn't associate the illness with swimming anyway). However, I CAN tell you from the experience of hot tub users that I tracked on poolspaforum.com that there were hot tub itch/rash incidents and one hot tub lung incident and one Legionnaire's Disease that nearly killed the person. I talked to these latter two people and to some of the others and believe me it's heartbreaking. Though most incidents were due to "too low or no chlorine" being used, some were from using "alternative" sanitizers.

Since the science shows that pathogens can live and grow in saltwater and since swimmers in pools are constantly shedding such bacteria (and viruses and sometimes protozoan oocysts) into a relatively smaller volume of water (compared to oceans, lakes and flowing streams), is your point that since there aren't consolidated reports of ill health from residential pools that we should not bother sanitizing them (since just using saltwater wouldn't be much better than fresh water)?

As for kill times, these are measured and well-known. One table of such times for some organisms is in this post where I reference numerous peer reviewed scientific papers in respected journals (though apparently that doesn't carry much weight as far as you are concerned). The kill times for chlorine are VERY fast and this is at a level equivalent to 0.1 ppm Free Chlorine (FC) with no Cyanuric Acid (CYA) so roughly an FC that is 10% of the CYA level. Even at that low chlorine level, fecal bacteria are killed with a 3-log (99.9%) reduction in under 1 minute. Half are killed every 6 seconds. Now in practice, some fecal matter is released in clumped form so it takes somewhat longer. Nevertheless, chlorine is used precisely because it kills faster that almost anything else that is reasonably safe for human exposure. And the greater risk, when it comes to bacteria, is that of uncontrolled growth since larger bacterial concentrations can overwhelm the body's immune system. Also, bacterial safety is also measured in real pools as part of having to pass EPA DIS/TSS-12.

There have been places, such as Australia, that tried using copper/silver since the combination (as you can see from the table) does kill though more slowly. Nevertheless, it is fast enough to prevent uncontrolled bacterial growth. What they found was that this wasn't good enough. It didn't prevent person-to-person transmission of disease and wasn't good at inactivating viruses so they pretty much ban its use in commercial/public pools and give strict warnings to those who want to use this in residential pools. Canada does the same thing.

Now if your argument is about relative risk, you can do whatever you want in your own personal residential pool, but there's no way that commercial/public pools are going to go to salt because all the evidence shows that it is not sanitary. If they go with some kind of alternative, it's not going to be salt, but more likely some other chemical combination like a quarternary ammonium compound along with potassium monopersulfate and with either UV or ozone in the circulation system, but only if they lower their standards for slower kill times.

As for the links of chlorine to bladder and other cancers, and since you have a degree in actuarial science, you should appreciate reading the Environmental Health Criteria 216 "Disinfectants and Disinfectant By-Products" document. The bottom line with the epidemiology studies (including the ones on bladder cancer) is that they varies so some studies showed possible correlations while others did not. Furthermore, in most cases the odds ratios were < 2 and often < 1.5 with wide variations (standard deviation) due to fairly small sample sizes. All of this often means that there are confounding variables not being taken into account.

For example, if someone finds a higher cancer rate for those drinking chlorinated municipal water compared to unchlorinated well water, the correlation may be due to municipal water servicing cities and most well water being in the country where people may do more physical activity. So the real correlation may be with exercise and not with chlorine. It's this kind of effect that makes epidemiological studies dicey unless their odds ratios are high with large sample sizes and having multiple studies looking at a variety of variables (e.g. studies about smoking and lung cancer and other effects).

[catfish]

My forum; my choice. Discussion of gastritis and the etiology of duodenal ulcers is not really germane here. If you want to start a swimming pool forum, where such things are considered OT, be my guest!

I'm not the one who brought up postmodernism.

[catfish]

I've already admitted that I didn't previously consider human to human transmission to be the primary focus of pool sanitation, in particular the survivability and transmissability of fecal-oral viruses surprised me. Unlike many a pseudorationalist, I readily admit my previous lack of knowledge / foresight. From the data you provided, it does indeed sound like a rather bad idea to use ocean level salinty in a public pool. (Though I was never thinking about public pools to begin with.) This does not justify the torpedoing of the entire concept, any more than the bladder cancer research means we should abandon all discussion and approval of chlorine. Anyone can quote statistics; the real challenge is in connecting the positive to the normative. Well no, I'd say the real challege is to intelligently interpret all data involved, and not just the ones you agree or disagree with. (Which was the only reason I brought up bladder cancer.)

So, there is still the unaddressed question of hypersaline concentrations (the extra buoyancy would be pretty fun too), and the completely different scenario that home pools present (half a dozen mostly related people who are already touching the same doorhandles vs. thousands of unrelated visitors every day.)

Thesis statement: Salt, along with some other metals, (bismuth ftw if only we could find some large deposits) has a number of extremely attractive qualities: relative lack of adverse human health effects, low cost (don't quote me tiny, overpriced bags of purified retail stuff), and the permanance / lack of maintanence because yes, people are lazy and stupid and real world risk analysis does not simply ignore operator error. It is foolish to ignore these qualities and write off the concept because:

1. OMG SALTWATER SHOULDN'T BE DUMPED ON THE GROUND (I think well publicized incidents of stupid people poisoning their own topsoil and wellwater will help drive this point home. Fortunately, there are plants like Salicornia to help with the cleanup.)
2. OMG SALT CAUSES RUST (meh, steel is overrated and overused anyway. composites ftw)
3. OMG SOME STUFF CAN SURVIVE IN OCEAN LEVEL SALINITY (see above)

[catfish]

Not wanting to spam, but I realize that nuanced reason can be tricky new territory for a data-spammer, so here is a more simplified version of my argument you have failed to rebut or even intelligently discuss:

1. A massive number of sources imply that dead sea level salinity all pathogenic organisms of concern (not considering massive discharges of sewage) on par with chlorine. I may be utterly wrong here; mainstream media sources can be easily wrong and I am not very familiar with the means by which saline deactivates some things.

2. Dead sea level salinity is affordable (if not the most affordable) for someone spending 5 figures on a pool.

3. Sodium chloride will be as affective as the magnesium salts the Dead Sea is dominated by.

There, all that distractingly eloquent language pruned. Happy?