Okay, How Does This Trick Work?

March 20, 2012 12:59 PM

What trick did the water sales person use today in my office?

Our Branch Manager, who does sales, was kind enough to meet with a representative (i.e., salesperson) from a company that sells systems that purify water from the tap.

After their meeting, the Branch Manager called us to the kitchen to show us the water that the sales person "tested." One cup had tested water from the tap and the other cup had tested water from our current bottled water system.

The tap water was a dark greyish color and had floating particles in it. The bottled water was light red (almost rusty) looking and also had particles in it.

Our branch manager said she ran it through a device to test the purity. This device was plugged into our work kitchen wall.

Now, what chemicals or additives did this person put in the water to show that it is supposedly impure? I'm curious as to how this trick works. A Google search provides me with a lot of warnings about duplicitous sales people for home water purification systems and little information about how this works.

I am guessing there is a chemistry trick involved here, I just want to know the exact methods. Obviously, I am advising her not to purchase the system and would like some idea of how we were duped.

posted by glaucon to work & money (30 answers total)

Can you run through the exact sequence of events, in detail?

Because what I'm envisioning two possible scenarios:

1. The salesman had two cups of dirty-looking water already there, and said "look, THIS is what your tap water looks like and THIS is what your bottled water looks like,"

or

2. The salesman had the two cups of water sitting there, and said "let me show you what's in the tap water," and dropped something into it with an eyedropper, and then did the same with the bottled water.

If it was the first scenario, it clearly could have been the salesman just dirtying the water before you showed up, and if it's the second scenario, then who knows WHAT was in the eyedropper.
posted by EmpressCallipygos at 1:02 PM on March 20, 2012

I don't know what she did, but the rusty looking water would probably be bits of iron oxide. However, having minerals in water is not automatically a bad thing, it depends on what they are and in what concentrations.
posted by DoubleLune at 1:06 PM on March 20, 2012

It was closer to the second.

I didn't actually witness it - the meeting was between the salesperson and our Branch Manager. From what my B.M. said, she watched the salesperson take samples from our tap and from our water cooler, and then ran it through a device that was plugged into the wall.

She claimed this device would help show how many PPM of various solids are in our drinking water.
posted by glaucon at 1:06 PM on March 20, 2012

From what my B.M. said, she watched the salesperson take samples from our tap and from our water cooler, and then ran it through a device that was plugged into the wall.

Ah -- how do you know what was really in that "device"? It could have been anything.
posted by EmpressCallipygos at 1:13 PM on March 20, 2012

What I'm trying to get at (because I realize I'm not being clear) is, I'm not so sure that you need any kind of specific breakdown of the trick, so much as just a good deal of skepticism.

What I mean is, this person is claiming, "look at all the particles floating in your water after I've tinkered with it!" But if the particles are only showing up after the person tinkered with it, maybe the tinkering is what put them there.
posted by EmpressCallipygos at 1:14 PM on March 20, 2012 [1 favorite]

Oh, I am completely skeptical - I know this is a slick sales trick. I just want to see if someone does have knowledge of how this works. I want to be able to say, "Hey, this is how it works, and that's why it's a waste of money!"
posted by glaucon at 1:20 PM on March 20, 2012

If a scam, it's probably something similar to the colon cleansing products, where the product itself (or the "testing solution") contributes to what you see.

I could see something reacting with the chlorine that's common in city tap water and causing precipitates in the solution, whereas the bottled water wouldn't have chlorine and thus no precipitates.
posted by jpeacock at 1:26 PM on March 20, 2012

If your goal is to show that the test was trickery, propose that your BM purchase a water purification test from a hardware store, and do your own test. I have no suggestions for brands, but they appear to be less than $30 online.

I don't know if anyone could know what was in that box, but I would discount the test at least some because it may have been contaminated by other people's tap water. An independent test would either back up the salesman's claim, or demonstrate that they are not to be trusted.

I might add that if you rent the space, any problems with your plumbing may be the responsibility of your landlord. And any problems with the bottled water would be their responsibility to provide clean water. Just putting it out there.
posted by China Grover at 1:30 PM on March 20, 2012

The salesperson may have used one of these: a precipitator. There's an electrochemical reaction between the precipitator electrodes and dissolved minerals in the water. The reaction products are colored, and they precipitate out as particulates. It looks like the electrodes are iron and aluminum. I assume that a lot of what's being produced are (soluble, brown) iron oxide species and (insoluble, white/grey) aluminum species.

If there are dissolved minerals in the water (any city water supply or bottled water), the reaction will proceed. Water purified by reverse osmosis or distillation will have very low mineral content, so there's no reaction.
posted by mr_roboto at 1:31 PM on March 20, 2012 [3 favorites]

The facts I read in this story are:
1. A salesman had a machine that "tested" water.
2. His demonstration of this system resulted in dirty-looking water.
3. Your manager witnessed this purity test.

What was the result of the purity test? What did the salesman say, and what conclusion did your manager draw from the test? "Your water's bad" would be the obvious conclusion, but who said it, based on what?

Because so far, I'm not sensing any trick, just a machine that dirties water.
posted by Rash at 1:31 PM on March 20, 2012

I'm hardly a chemistry whiz but I might suspect it had something to do with the cups or bottles the water was poured into. Maybe there was already something (a drop food coloring) in the bottom of the cup?
posted by halseyaa at 1:33 PM on March 20, 2012 [1 favorite]

What was the result of the purity test? What did the salesman say, and what conclusion did your manager draw from the test? "Your water's bad" would be the obvious conclusion, but who said it, based on what?

It was, "Your tap water is bad! Why? Look at the dirty water! That means there must be a lot of dissolved solids in PPM!"
posted by glaucon at 1:34 PM on March 20, 2012

I'm hardly a chemistry whiz but I might suspect it had something to do with the cups or bottles the water was poured into. Maybe there was already something (a drop food coloring) in the bottom of the cup?

My B.M. said the cups were clean.
posted by glaucon at 1:35 PM on March 20, 2012

>It was, "Your tap water is bad! Why? Look at the dirty water! That means there must be a lot of dissolved solids in PPM!"

And the person who said this was the salesperson (of course she came to this conclusion!)
posted by glaucon at 1:36 PM on March 20, 2012

That means there must be a lot of dissolved solids in PPM!

Yeah, there's a much higher level of dissolved mineral species in tap water than in deionized or RO water. Orders of magnitude higher concentrations. This is true, and it's probably the principle on which the demonstration works. If you need water with a low mineral content, you need to purify it by RO or distillation.

The catch is, these dissolved minerals aren't harmful to human health, so unless you're using the water to do chemistry, or boiling off large volumes and are worried about leaving residue in your boiler and pipes, there's no reason to purify further.
posted by mr_roboto at 1:39 PM on March 20, 2012 [7 favorites]

The other thing to note: deionized water has its drawbacks. It tastes awful (just my opinion), and since it has such a low mineral content, it will leach minerals from whatever it comes in contact with. If you try running DI water through copper piping, it will eat up your pipes right fast.
posted by mr_roboto at 1:42 PM on March 20, 2012 [2 favorites]

The other thing I noticed was that the tap water sample was warm. She (the salesperson) had drawn warm tap water instead of cold because warm tap water typically has more dissolved solids than cold.

The catch is, these dissolved minerals aren't harmful to human health, so unless you're using the water to do chemistry, or boiling off large volumes and are worried about leaving residue in your boiler and pipes, there's no reason to purify further.

And that's what is so frustrating! My manager is all on board for a new system, and someone I work with (who has a touch of OCD) is now worried about the water.
posted by glaucon at 1:49 PM on March 20, 2012

A pH tester will also change the color of water, not sure why they had to run the water through a machine though.
posted by wongcorgi at 1:55 PM on March 20, 2012

If people are worried about the water, perhaps proposing "why don't we just get some Brita filters" may support your case. I'm sure having the filters on hand would be a lot cheaper, and if you can't get 'em to understand the science, try using the bottom line.
posted by EmpressCallipygos at 1:55 PM on March 20, 2012 [1 favorite]

"Your tap water is bad! Why? Look at the dirty water! That means there must be a lot of dissolved solids in PPM!"

I have actually done drinking water quality testing. This is stupid, and the "in PPM" thing is especially wacky. PPM just means parts per million. It's a unit of measurement. It's meaningless without an actual quantitative measurement to attach to that unit. "Longcat is really long; he has a lot of length in meters!"

For calming people down: I think your best bet may be to combat this scammer with actual SCIENCE. Or at least with laboratory testing results.

You are almost certainly on public water, yes? If so, Google "[name of your town] drinking water quality report" and you will get the most recent drinking water quality report for your local utility, the folks who actually supply drinking water to your office. They sample your town's water on a regular basis. They will have a nicely produced report you can print and show everyone.

Two special cases where you may be on public water and it still might be worth being a little more worried:

-If you are in an older building in a town with known lead in drinking water issues. If this is true, your drinking water quality report will note it and there may be a local program that provides lead testing kits (like there is, for example, in NYC).

-If you have an older drinking water fountain (like pre-1980-ish) that doesn't get used very often. Sometimes these units can leach lead into the water sitting inside the unit. The fix to this is very simple -- let the water run until it's cold before drinking. But if you're worried, you can see if there's a public program to help, or even just buy a testing kit at Home Depot.

If you actually are on well water, it's a little more complicated, but only just. Call the local environmental health department and find out (a) if anyone requires regular testing for your well, and (b) if they have a program to help you test the well water if the well isn't required to be sampled on a regular basis. If you work in PA, and the well is a public water supply, there are regular sampling requirements and the sampling reports should be available on the PADEP website. (It's a bit non-obvious to find -- call the PA DEP main number and explain what you're looking for, and they should be able to get you to it.) If the well is only supplying a few people, well, that's when you ask the Environmental Health people to walk you through testing it for drinking water parameters. Doing that will be a lot cheaper than this treatment system. And if you do have a problem, you'll be able to get a system that's appropriate to your specific issues.

I am an environmental consultant; I am not your environmental consultant. YMMV. When in doubt, I am always a fan of calling your local county environmental health folks, your water utility, and/or your state environmental folks. They may not be the right people, but they can get you to the people who are.
posted by pie ninja at 2:08 PM on March 20, 2012 [11 favorites]

Your public water company will have a detailed report of the water quality, You an probably get it online, or call them and ask for it. They're water quality geeks, and will spend all sorts of time telling you about your municipal water supply.
posted by theora55 at 2:09 PM on March 20, 2012 [1 favorite]

I can't remember the name of the company selling this off the top of my head, but it's a pretty recent MLM scam. I have a Facebook friend-of-a-friend that posted about this (they were selling it) a while back.
posted by chrisfromthelc at 2:49 PM on March 20, 2012

Another possibility: the salesperson's device actually ADDED something to the tap water when that water was run through it --- the water was fine going in, but instead of that device filtering out precipitates it did the reverse and added some.
posted by easily confused at 3:36 PM on March 20, 2012

Here's a fascinating bit the CBC did on this last year. (I hope you can access it.)
posted by Mrs. Rattery at 5:24 PM on March 20, 2012

Look, they probably were able to precipitate minerals that were dissolved in the water, and there are a couple different ways to do this. Some people think it is a trick. The fact is, this isn't a trick. The minerals are in the water, and the purification systems will remove it. Where sales people become dishonest is in making the precipitation result seem more significant than it is.

Now, the question is, are those dissolved minerals harmful, or do they taste bad? They are probably not harmful. They can make your water taste bad. Your manager will have to decide if that is worth the cost of a purification system. If you think your water tastes bad, then it may be worthwhile to purify your water more with a simple filter. But beyond that? Your water is probably fine in your office.
posted by nasayre at 5:53 PM on March 20, 2012

There's a lot of Wooo on the web on this subject, but arguably drinking distilled or deionized water would tend to rob you of a lot of key minerals you're currently getting. Unless this sales person can explain to you in clear unambiguous language (feel free to mefimail me) why this test detects, oh, mercury, cadmium, lead and arsenic, but not iron, manganese, zinc and magnesium (just picking some random essential trace elements) then the sales person is more or less practicing a brand of science I like to call "making shit up".
posted by Kid Charlemagne at 9:02 PM on March 20, 2012

From my friend who sells these systems:

It’s not a trick and they’re not ‘adding’ anything to the water. They’ve plugged in a conductivity device then stuck it in the water – two rods, one charged with negative ions, one charged with positive ions. It basically tests the conductivity of the water (and conductivity is basically measured by the amount of non water particles in water). The rods create a charge between them and this charge burns up these particles hence making them become visible and changing the colour of the water depending on what’s in it.

It IS a technical thing to do to water but also makes an awesome party trick.
posted by travellingincognito at 9:44 PM on March 20, 2012

Check this site: watertestscam.org.za - and there's a lot more out there about this particular way of foolin' ya.
posted by drhydro at 11:37 PM on March 20, 2012 [1 favorite]

Your public water company ... They're water quality geeks, and will spend all sorts of time telling you about your municipal water supply.

They may even offer you a free tour of the water treatment plant that processes your very water. Field Trip!!
posted by CathyG at 2:59 PM on March 21, 2012

It’s not a trick and they’re not ‘adding’ anything to the water.

Bullshit. They're adding aluminum and iron ions to the water. That's why the rods get depleted and need to be replaced.

The rods create a charge between them and this charge burns up these particles hence making them become visible and changing the colour of the water depending on what’s in it.

You have no idea what you're talking about.
posted by mr_roboto at 11:19 AM on March 22, 2012