Bit of a con or sharp practice on water filters.

[Robert Atkinson 2Participant @robertatkinson2]

The other half bought a new Brita water filter jug recently. She asked me to “fit this electronic indicator” I though, great they have a conductivity sensor to tell you when the filtered water isn’t up to specification and you need to change the cartridge. Investigation showed no sign of electrodes. It’s a little sealed module with a clear button that has a multicoloured LED behind it. According to the instructions when it flashes green all is OK, amber get a new filter and red replace the filter. So how does it work? A bit of experimentation shows it’s a tilt sensor. So if you pour X times it goes amber, Y times it goes red. Trouble is it doesn’t know if you tilted it to pour water out or tilted it to fit under the tap to fill it. I’ll give them the benefit of doubt and assume they at least time the pour.
However there is no way it can tell the quality or mineral content of the water you are filtering. This has a significant effect on filter life. There is also way of it detecting if you used a basic filter or one of the enhanced ones. Call me cynical but it looks like a good way of getting consumers to buy new filters before they are really needed. It would be just as easy to actually measure the water conductivity and give a real indication of filter performance. OF course that would lead to selling fewer filter cartridges.

Robert.

[Andy StopfordParticipant @andystopford50521]

There is a possible way this might work.

You can buy, or make, a device called a tilt hydrometer which you can use to monitor the changing specific gravity of fermenting beer.

It uses a floating tube which is weighted to float at an angle on the surface – as the gravity changes, so does the metacentric height, the angle of float changes, and an accelerometer within measures this to calculate the gravity (the temperature is also measured since this needs to be corrected for).

Here’s a link to a DIY version:

https://github.com/universam1/iSpindel

Does the Brita cartridge detect the slight changes in gravity which presumably should occur if it’s doing its job removing dissolved solids? Well, maybe…

[BazyleParticipant @bazyle]

Does the blurb give an indication of how much it treats? Like ‘provides you with 500 litres of water’ and hence how many jugs-full it is counting. Then you could mount it in the lathe 4 jaw and set it rotating in back gear for the appropriate number of revs.

[John HaineParticipant @johnhaine32865]

In my experience Brita jugs are designed with built in obsolescence as the plastic fractures where the handle joins the body at a sharp corner.

[DiogenesParticipant @diogenes]

A natural evolution of events from the ‘Printer Cartridge’ world – I’m sure that soon many more devices will come with this sort of ‘helpful’ functionality..

..power tool batteries have to be a good bet – “Dear Customer, your battery’s recharge cycle lifetime is almost up – to continue receiving the level of performance that you expect from your XxXxxx equipment, please contact your local service agent.. etc.. “..

 

[JasonBModerator @jasonb]

But they may have done some testing on how many times people tilt the jug and set it up on average together with an average volume treated depending on tap content. So some may be changing before it is needed but others after it is needed.

Looking at their website the jugs and the table top ones with a tap use the same filters so as you don’t tilt the table top ones there may be more to it than a tilt switch.

Me I’ll just drink the tap water.

[Robert Atkinson 2Participant @robertatkinson2]

The unit had no contact with the filtered water. Water purity doe not detectaly affect density at these levels.
You can reset the unit by holding the button down.

It does not know what filter type is fitted.

Any inaccuracy will short change the consumer. Either they are replacing good filters or drinking water which is not as filtered as they expect. It appears a “high tech” solution so consumers wll trust it.

A conductivity based indicator will give correct results and is not a technical challenge.

Robert.

[bernard towersParticipant @bernardtowers37738]

Mine is just monthly with 4 bars as indicators, had it for years (not with the same filter in it)

[larry phelan 1Participant @larryphelan1]

Robert, I think you have got it in one !!!

[SillyOldDufferModerator @sillyoldduffer]

Measuring the life of a filter in months is low value because life depends on how much water passes though it, how contaminated the water is, and what with.  All unknown!

The simple counter identified by Robert is slightly better than replace after elapsed time because it sort of measures the volume of water filtered.   Much used filters are counted down faster than a little used ones.  Crudely!   The counter knows nothing else about the water.

Water filters are dubious in themselves.  Most Western countries deliver potable water straight from the tap, and it can be drunk fearlessly.   I’ve heard some people shower in it too!   Filters appeal partly to people who don’t trust the water system, and partly to those who can taste the difference or believe they can.

I live in a limestone area where tapwater contains minerals, chiefly Calcium.  It alters taste and feel compated with soft water, and doesn’t go well with some teas.   (Yorkshire Tea is good in Somerset.)  Medical evidence suggests Hard-water is good for us, and super-pure water damages kidneys.  Chlorine can sometimes be tasted in tapwater, and if so, the right kind of filter should help.

But beware, in a double blind test, most people can’t tell the difference between tap water and filtered tap water.  Suggests most filtering is a waste of time and money; they are a placebo.   However, a proportion of double blind testers can tell the difference, and maybe you’re one of them.  And then, placebo benefit being psychological rather than real is no reason to ignore it; if filtering keeps one happy, then go for it.  (Curiously a proportion of people in trials continue to believe in placebo medications, even after being told they’re neutral.)

All a bit of a con, but there are reasons for choosing to buy bottled water and filters.

Dave

 

 

 

[Martin of WickParticipant @martinofwick]

As sod says – a right con!

As far as I can tell from the vacuous blurb on their site, the term ‘filter’ is used loosely and is mainly some basic ion exchange to reduce the carbonate / bicarbonate  / chloride/ sulphide content.  Bear in mind the  health risks associated with drinking only soft water though!

Ineffectual as far as removing the much more unpleasant  nasties that sometimes appear in minute quantities in drinking water  (cryptsporidium, hydrocarbons and aromatic hydrocarbons etc).Ultrafiltration, UV and activated carbon filtration is required to remove those. Fortunately, most water companies do that for us.

Always thought hard water makes good tea (and beer) and it was soft water that made most teas taste like boiled grass. Never knew they could grow tea in Yorkshire though.

[duncan webster 1Participant @duncanwebster1]

I’ve read that Yorkshire tea is blended differently for hard water areas, so do your research before going away for a holiday, you might be better off buying locally than taking it with you.

[BazyleParticipant @bazyle]

When I were a lad the new village reservoir was piped from a bog off the edge of one of the tors up on the moor and the local lads would sometimes fill the feeder pipe manholes with cowpats. The water had less iodine (from the radioactive radon in the granite)  than the old wells so goitres were no longer common except in the older population.
Then they built a new treatment works and filled the water with chlorine, SO2 and chalk. We still have the remains of two communal village pumps.
In parts of London they say the water has been used 6 times before you get it – so you know it is safe to drink 🙂

[JasonB]

On JasonB Said:

 

Me I’ll just drink the tap water.

Me too.  It’s probably safer.  The chlorine in tap water is not a contaminant.  It is added for a good reason in that it kills bacteria.  If it is removed by the charcoal filter any bugs still remaining could start multiplying again.

Russell

[Martin of Wick]

On Martin of Wick Said:
As sod says – a right con!

As far as I can tell from the vacuous blurb on their site […]

That said … It’s worth looking at some of the BRITA patents on espacenet

… There are mind-bogglingly clever people somewhere in that organisation.

MichaelG.

 

[Grizzly bearParticipant @grizzlybear]

@robertatkinson2,

Is it made by one of the robbers that sell printers?

[Robert Atkinson 2Participant @robertatkinson2]

SOD,

We are in a hard water area and filtering the water make a big difference to tea, cofffee and the life of the kettle and steam iron. We don’t drink cold water from the filter jug or use it for cooking. .

Bazyle,

There is no Iodine, stable, or otherwise in the Radium 226 decay chain. Radon is second in the cain and the final, stable, isotope is Lead. Intermediates are various isotopes of lead, Polonium and Bismuth.

Russell,

Any bacteria left in the water would need time to multiply and I can’t think why you would leave it that long. Once out of the tap the Chlorine soon dissipates from the water. More likely to get contaimination into it from hands etc after that.

I realise I must sound like a know it all at time and what would an aerospace engineer know about that? However I’ve had some time out designing biotech instrumentation and had some fundamental training in such matters. I’ve done research and invented a patented sterilisation device.

G.Bear. As mentioned at the start it’s a Brita.

Robert.

[BazyleParticipant @bazyle]

Thanks for the info Robert. It turns out it is the opposite, lack of iodine that can be a problem There was a lot of fuss made about the radon in the water at the time they put in the new reservoir in the ’60s so it might have been a ploy to get the village to accept the disruption. Live and learn 60 years on. Dartmoor prison is currently closed owing to radon problems.

[Nigel Graham 2Participant @nigelgraham2]

How does a filter remove dissolved minerals?

Microscopic precipitates maybe, but I was always taught a solution cannot be separated by filtering.

 

Regarding radon, that is a gas. I do not know how soluble in water it is, but I would expect it to come out of the water by drop in pressure, heating or just standing. Not by filtering, though the filter surface might help it come out of solution.

It is most significant in areas with large masses of granite and its surrounding metamorphic rock, or certain metal ores, at shallow depths, as in Cornwall. For the metals, also some of the Carboniferous Limestone regions with heavily-mineralised strata. I would have thought dissolved metal salts more worrying, by amount and exposure.

Radon’s hazard in buildings lies in it accummulating in e.g. basements and cellars; or rooms with poor ventilation.

[John HaineParticipant @johnhaine32865]

These filters use a mixture of activated charcoal and ion exchange resins, so they effectively soften the water and remove chlorine. Makes much better tea and coffee and better tasting water.  Our Brita broke and anyway was a recycling nightmare.  Now have a Phox which uses a refillable filter and little paper bags of mixture you empty into it.

[Nigel Graham 2]

On Nigel Graham 2 Said:

How does a filter remove dissolved minerals?

Microscopic precipitates maybe, but I was always taught a solution cannot be separated by filtering.

Unless an active filter is used.   The filter isn’t a simple net, it contains chemicals that do ion exchange and other tricks.  Not difficult to remove Chlorine which some people can detect in small quantities.

 

Regarding radon, that is a gas. I do not know how soluble in water it is, but I would expect it to come out of the water by drop in pressure, heating or just standing. Not by filtering, though the filter surface might help it come out of solution.

Water pumped from underground where the underlying geology has Uranium often contains dangerous levels of Radon.   Granite and other ancient rocks are enough underneath limestone, so worth measuring it, and if found dispersing it at the water works rather than allowing it to get to our taps.

Radon being a noble gas doesn’t react chemically with anything, so if it does arrive at the tap an ordinary active filter won’t stop it.   Nasty stuff to have inside the body whether breathed or drunk.   Though manageable, Radon will be one of the reasons nearly half of all UK residents get cancer in some form.  But it’s not a big killer compared with smoking, booze, poor diet, solar radiation, industrial processes, and pollution.

…

Although filters are mostly a con, they’re not completely so.   Robert can tell the difference, which is a good reason for using them.   His tap-water is different to mine, quite possibly needing a dash more Chlorine than mine does to kill bacteria and viruses.

What is worth doing here is reducing the temperature of water when making coffee or peppermint tea.   Whilst proper tea must be made with fresh boiling water in a pre-heated pot and not allowed to stew, coffee tastes better made with fresh water at 85°C.   Though my relatives say they prefer cool made coffee to hot too, they might be indulging me!  So I’ve no idea if the observation is valid outside my kitchen.   Taste is highly subjective.

Dave

[Grizzly bearParticipant @grizzlybear]

Robert,

That was wasted, I was thinking Printer ink.

Comparing it to rip off filters.

Bear…….

[duncan webster 1Participant @duncanwebster1]

According to  https://www.ukradon.org/information/privatewater#:~:text=Most%20drinking%20water%20supplies%20have,need%20to%20take%20any%20action.

Drinking water with dissolved radon is a much smaller problem than showering in it. It also says public water supplies are not a problem, but private borehole might be

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