OT: Filter vs R/O

Jim Thompson

unread,

Jun 12, 2013, 1:17:07 PM6/12/13

to

Jeff Liebermann

unread,

Jun 12, 2013, 2:04:22 PM6/12/13

to

On Wed, 12 Jun 2013 10:17:07 -0700, Jim Thompson
<To-Email-Use-Th...@On-My-Web-Site.com> wrote:

>Anyone have views about which is best for drinking water...
>multi-stage filters or R/O?
> ...Jim Thompson

You're in solar country, where a solar distillery is both cost
effective and practical. In your area, my guess(tm) is 2-3 gallons
per day from a small backyard still, which should be enough for
cooking, drinking, and chemistry experiments.
<http://www.i4at.org/surv/sstill.htm>

I have a small multi-stage, stainless can, drinking water filter thing
somewhere. I ripped it out after I discovered that the filters cost
about $85/ea and only last about 250 gallons. The flow rate was also
really slow. Filling a tea kettle took much longer than my patience
would allow. I eventually resorted to pre-filling a gallon plastic
container, and dispensing the water from it.

I'm now looking at multi-stage filters with separate cartridges for
removing the rocks, and another for taste (activated charcoal). The
local water is clean enough that I don't worry about bugs. Hopefully,
that design will also be cheaper.

I also had an odd problem with the filter. I washed the stainless
parts with acetic acid (vinegar). No problem except that everything
taste like vinegar for the first 100 or so gallons. Also, when
installing a new filter, I'm expected to flush about 50 gallons
through the filter before it's happy. No thanks.

When you settle on a filter or filter type, you'll find various online
charts for different types of filter cartridges, including
multi-stage. Some simple filters (i.e. Pur) simply remove the rocks
(euphemistically called sediment). Others a sub-micron filters and
will remove bacteria.

The problem with reverse osmosis is that it draws 500 watts when
running and therefore can cost too much in electricity. The main
benefit to RO systems is the high capacity, which you probably don't
need. There are also a few consumables (chemicals) that add to the
cost. When you blow out a membrane, say goodbye to about $150. RO is
nice, but methinks overkill for just drinking water.

Run your own numbers for reverse osmosis and see where you land:
<http://www.gewater.com/rotools/fillCostOfOperations.do?step=step0>
Also, cleaning out the tanks with vinegar every 90 days is not my idea
of fun.

Comparison of various water filters:
<http://www.guide2waterfilters.com/compare-leading-brands/>
<https://www.airandaqua.com/index.php?l=page_view&p=water_filter_comparison_chart>
<https://www.google.com/search?q=water+filter+removal+comparisontbm=isch>

If you can't decide, there are filters that will filter almost
anything. Here's a 7 stage system that includes reverse osmosis:
<http://www.pristinehydro.com/water-purification-systems/>

If bugs in the water are a problem, you might also look into UV water
purifiers, which are sometimes built into the filtering system, but
more often a separate cartridge or assembly. Except for camping, I
have no experience with UV:
<http://www.pelicanwater.com/whole_house_water_filters_uv.php>

--
Jeff Liebermann je...@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

Martin Riddle

unread,

Jun 12, 2013, 9:15:15 PM6/12/13

to

On Wed, 12 Jun 2013 10:17:07 -0700, Jim Thompson
<To-Email-Use-Th...@On-My-Web-Site.com> wrote:

>Anyone have views about which is best for drinking water...
>multi-stage filters or R/O?
>
> ...Jim Thompson

R/O
Unless you like to add minerals for taste, then the multistage filters
will do that for you.

R/O will also filter out most of the bacteria. If the filter isnt
perfect, then some bateria will get thru. I guess it's practical for
the smaller sink top drinking taps.

Cheers