Testing Water Filters

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Correllux
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Important to note that most filters will not do viruses - at all.  Purifiers might (depends). 

The finer filters like those for backcountry water go down to about 0.2 or 0.1 microns these days.  That handles the majority of things but the type of filtration device and media, plus how it's used determine the effectiveness.

For viruses you need a minimum of 0.02 and 0.01 is the accepted standard.  This reduces flow rate considerably, and if the water is not nice and pristine-clear then of course you get quick clogging.  The media for this super fine filtration is usually polyester felt, pleated. 

That said, the much "larger" standard filters may get some viruses trapped or stopped.  This is more likely with depth media like those carbon filters that are 1/2" thick or better.  With the more popular and cheaper hollow fiber membrane (tubes) media now, there's really no hope for viruses to be caught and if users force water under higher pressure than the tubes can withstand before the pores expand, then in that case zero viruses and also a good chance that some smaller bacteria may make it through.  (this is one reason that "absolute" should never be used with this type of media...but tell that to Sawyer who popularized it....Sawyer sucks for tech knowledge and honesty/transparency...although their products are generally ok).  But...viruses typically don't float around on their own in the world but are usually attached to other larger particles that the filter may catch - no guarantees, however, and also no guarantee that in subsequent use that the virus may be forced off of its particle and into the flow.  The other hope is that with mineral buildup (or god forbid, biofilm) some viruses and other things smaller than the filter pores may get caught then, but at that point you have other issues to address.

That dye in the PF video?  Much much finer than viruses....and it's not really a particulate, which is why almost nothing removes it.  Same for kool-aid and many drink products...they'll come through the same color when they exit a filter. 

Also, minerals in water, dissolved or in particulate form, do not equate to a guarantee of stones in the body or any other harm.  There are many types of stones (in a whole rainbow of colors!) and how they are formed is generally not what you would think (e.g. you are what you eat) although sometimes it can apply. 

I've not read about this...what's the thinking about pure water being harmful for the body?  A little more acidic than with added minerals, or what?

Forsythe P. Jones
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I’ve not read about this…what’s the thinking about pure water being harmful for the body?
The claim I’ve heard is that pure water somehow leaches minerals from your body if the minerals are not already in the water.

Hmm, maybe there is something to it. I found this with a web search and haven’t read it yet: https://www.who.int/water_sanitation_health/dwq/nutrientschap12.pdf

Bort
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zoulas wrote:
Bort wrote:
zoulas wrote:
Guys, just like we all know the flashlight with the highest lumens is not always the best flashlight, can we agree that the water with the least amount of dissolved solids is not always the best water? Are we in agreement with this statement? Can we also agree that some dissolved solids are good for you and that removing them would be a bad thing? Can we agree on that statement?

No, i cannot agree on these things.

The minerals that cause hardness are not vital to humans (nor are they unique to hard water) and we don’t add them to the water in places that naturally have softer water becasue their citizens are not suffering from lack of hard water.

They may have some moderate benefits but even that is tenuous.

He did not measure harness. He measured dissolved solids.

He played a game of statistics with his audience. People relate to numbers whether it’s horsepower, temperature, or lumens.

Quality water has minerals that you need. These minerals contribute to dissolved solids in water. I want those. I don’t want radioactive dissolved solids though.


Minerals that cause hardness are part of the TDS measurement but are not the entirety of it.

The Journal of Alternative Facts TM

"It is critical that there is a credible academic source for the growing and important discipline of alternative facts. This field of study will just keep winning, and we knew that all the best people would want to be on board. There is a real risk in the world today that people might be getting their information about science from actual scientists"

 

 

 

Bort
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Forsythe P. Jones wrote:
Quote:

I’ve not read about this…what’s the thinking about pure water being harmful for the body?
The claim I’ve heard is that pure water somehow leaches minerals from your body if the minerals are not already in the water.

Hmm, maybe there is something to it. I found this with a web search and haven’t read it yet: https://www.who.int/water_sanitation_health/dwq/nutrientschap12.pdf


People who start with a conclusion and work backwards can interpret evidence to get the conclusion they started with.

The Journal of Alternative Facts TM

"It is critical that there is a credible academic source for the growing and important discipline of alternative facts. This field of study will just keep winning, and we knew that all the best people would want to be on board. There is a real risk in the world today that people might be getting their information about science from actual scientists"

 

 

 

Correllux
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Forsythe P. Jones wrote:
Quote:
I've not read about this...what's the thinking about pure water being harmful for the body?
The claim I've heard is that pure water somehow leaches minerals from your body if the minerals are not already in the water. Hmm, maybe there is something to it. I found this with a web search and haven't read it yet: https://www.who.int/water_sanitation_health/dwq/nutrientschap12.pdf[/quote]

Doesn't seem very useful and it isn't research findings, per se, just review of many aspects over many decades, most of which don't seem to be entirely applicable.  It's focused only on ingestion of water and the possibilities (that word is used in most of the chapter) of leached metals - which is a legit concern - and reduced minerals via consumption.  It ignores human physiology and food intake, though, but I can see where it could be of concern in people that have exceptionally poor diets/food choices or where malnutrition and low caloric intake is the norm (and it's sad that should be the norm anywhere...). 

I may dig around a little more on the subject this weekend...definitely don't want to wallow in a rabbit hole of alternative health pundits, though.  Certainly open to learning but there is so much uneducated bunk hypothesis out there these days and people take it hook, line, and sinker. 

 

For my water at home, I've been using carbon filters for the last 30 years or so, and it's just for taste and reduction of chlorine byproducts, whatever silt or particulates are floating about, and hopefully any lead making its way through the system.  I learned more about this stuff from lab work and years of backpacking and I'm glad I had some of the resources I did...and that most of that was before the huge change in marketing came about.  Tough to find good legit knowledge these days and to wade through all the muck of misinformation or underinformation. 

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Water quality is a hotly debated moving target I think. Well around here it is anyway. I can tell you what has worked for me over time in two particular situations.

The farm: The well water is pretty clear so that makes it easier. Right out of the well the water hits a 25 micron filter and goes to outside faucets, sprinklers, and water troughs for the animals. After that it heads inside the house where it hits a 5 micron filter and a Uv loop. It then goes to the indoor fixtures. The Uv lamp is changed yearly and will kill pathogens at up to a flow rate of 15 gal/min. The 5 micron filter lasts about two years, sometimes longer. No chlorine, iodine, or water softener is used. Every year I send a water sample to the county extension service for testing. The results are thorough and it costs about $80. If there are any red flags I’ll hear about it. If we had sulphur or something disagreeable like that we would use charcoal. Been lucky that way.

Wilderness trips: In the old days I added 6 drops of fresh chlorine per gallon of water with a contact time of at least 24 hours in order to kill waterborne pathogens. Cloudy water is settled in buckets overnight and the clear water decanted off in the morning before adding chlorine. I hate the taste and smell of chlorinated water so three capfuls of hydrogen peroxide per gallon is added to the water after the chlorine has done it’s job for a day. This deactivates the chlorine and imparts a nice sweet taste to the water. Won’t hurt you none. 4 hour contact time for the peroxide. I used the Katadyns and other filters for many years with success, but it’s a lot of time and work. Nowadays I start with clear water and use a Steri Pen, available at Amazon and other places. It’s quick, easy, and requires no other chemicals in order to kill pathogens. Care must be taken not to cross contaminate. In all these years no one has gotten sick from any of my water thank goodness. Some have turned a shade of green listening to my tired old camp stories though.

I use the Steri Pen Opti Adventurer
Steri pen

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That was a disappointing review dissolved solids are not a great benchmark. I would be more concerned with things like heavy metals, chloramines VOC’s and various other chemicals which would not AFAIK register on that cheap (free with a filter) TDS meter he had.

I point to others in this group to justify how many flashlights I have.

my9221
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Asbestos wrote:
That was a disappointing review dissolved solids are not a great benchmark. I would be more concerned with things like heavy metals, chloramines VOC’s and various other chemicals which would not AFAIK register on that cheap (free with a filter) TDS meter he had.

I agreed!

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