Can I Use Salt As Sanitizer Instead of Chlorine?

[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!

[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.

[BigTallGuy]

I said it once and I'll say it again. There is no "FREE LUNCH" when it comes to swimming pool sanitation. You're gonna pay the price somewhere, somehow, but burning my skin is not a price I want to pay.

[chem geek]

It doesn't help to move the goalposts around, so to speak. We started out talking about ocean salinity levels, but yes if we are talking about extraordinary salt saturation levels nearly 10 times higher then sure that may kill pathogens, but as was pointed out by others above is impractical for many reasons.

If we want to have a rational discussion about chlorine alternatives, we can have that, but why waste time going down dead ends? There are already quite a lot of alternatives we can discuss unless we're just having a brainstorming session online.

I didn't mean to discount the very real risks of chlorinated disinfection by-products. High bather-load indoor pools that aren't exceptionally well managed can be pretty darn awful in short-term effects (largely from nitrogen trichloride) and may be at least somewhat harmful for long-term effects (from brominated THMs and other chemicals, mostly regarding cancer). However, when I look at this data, I can see that reducing the active chlorine level to the lowest amount that still gives reasonable disinfection rates while simultaneously providing methods for removing organic precursors (i.e. bather waste) to oxidize them before chlorine does seems the easiest path to take, at least initially. I believe small amounts of CYA (20 ppm for indoor pools, for example) can be used for this purpose to have, say, the equivalent of 0.2 ppm FC with no CYA.

As for true alternatives, we need something for bulk-water disinfection and right now it looks like the quarternary ammonium compounds might be a reasonable candidate (I already discussed the problems with copper/silver, though for just preventing uncontrolled bacterial growth they are OK if one can deal with their levels and pH to avoid staining issues). UV or ozone can still be used to handle Crypto. That still leaves general oxidation of bather waste for which there are a lot of alternatives (ozone doesn't oxidize urea well, especially if it's not chlorinated, while UV only affects some chemicals). In addition to some selective oxidizers, such as MPS, the use of boron-doped diamond electrodes to produce hydroxyl radicals may be a good approach and might be one of the few things that can break down urea (other than chlorine, which does so slowly though possibly aided by the UV in sunlight that produces...hydroxyl radicals), though that remains to be seen.

And then there's the DIN 19643 system used in some countries in Europe that focuses on coagulation/filtration for removal of organic precursors, though they use low levels of chlorine in the 0.3 to 0.6 ppm FC range without ozone or 0.2 to 0.5 ppm FC with ozone (with no CYA, however, so still generally higher than I'm proposing).

Now for residential pools where person-to-person transmission of disease is a risk many would be willing to take since odds are they might catch something through other contact means (such as you described), then the focus is more on preventing uncontrolled bacterial growth and oxidation of bather waste. The same sorts of alternatives as described above could be used, but using a subset of them since the bather load is much lower. Just keep in mind that the risk is higher (though as a personal choice, may be acceptable) and usually the costs will be higher as well, at least up-front. I'm just very leery given my discussions with users of such systems when they failed, but realistically a properly designed system may not have the same problems as those that were used (or used improperly).

[waterbear]

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

In other words, a bean counter for the insurance industry! Explains a lot. A FAR cry from the actual hard science disciplines like chemistry, biology, and physics. More akin to an accountant that understands some statistics.

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

well, it shouldn't.

Probability is better left to describing an electron's position in its orbitals or perhaps at the roulette wheel and craps table in Vegas (or to the insurance industries, which is basically just another form of gambling, that are betting that they can get your money without having to pay you for a claim. If you are high risk they won't insure you!) then to the care of a swimming pools!

[AnnaK]

Putting down someone's educational achievements, the job he holds, and the industry in which he works really isn't germane to this discussion.

[waterbear]

I was merely pointing out that his expertise is in a different field and not one related to pool water sanitation such as chemistry, microbiology, medicine, etc. or even pool maintenance and operation for a variety of pool and not just his own.
His expertise would be in accounting and risk management (which is where the probability comes in).

I stand by everything I said and it was not a put down. It was a statement of fact. Just because one has higher education does not make them an 'expert' in areas not related to what they studied, not does it necessarily give them critical thinking skills (particularly nowadays).