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From: John De Armond
Newsgroups: rec.outdoors.rv-travel
Subject: Re: Water filtering for a RV
Date: Sun, 25 Sep 2005 03:20:27 -0400
Message-ID: <>

On Sat, 24 Sep 2005 22:37:15 -0400, Sandy A. Nicolaysen
<> wrote:

>On Sat, 24 Sep 2005 17:54:16 -0400, Neon John <> wrote:
>>I developed a tasted for distilled water when I lived in PA where the
>>water wasn't fit for man nor beast.  I've continued ever since.  I
>>have a floor-standing unit that can make 10 gallons a day and holds 20
>>gallons in a tank.  I also have a small stove-top unit that is very
><snipped for brevity>
>John:  Thanks for the info.  A quick question.  Since a distiller
>seperates the pure water from the other nasty stuff, surely this thing
>needs to be cleaned out on a regular basis?

It does.  My first still in PA looked like one of those church coffle
percolators that makes 50 cups or so.  Even though the boiler had
continuous blowdown (feed and bleed), I removed a mason jar's worth of
crud from the boiler every month.  The larger one, the one I have now
does not have blowdown but instead has a boiler drain valve. I open
that every month or so and flush the boiler with clean water.  In PA I
had to do that once a week or else the solids would build up enough to
burn out the element (a 120 volt water heater element).  The water is
much better here so once a month does it.  The stuff comes out a milky
orange rusty looking stuff.  And to think others are drinking that
stuff!!  I use distilled water in my steamers in the restaurant so a
month is probably 100 gallons' worth of water processed.

About once a year, I open the boiler's cleanout hatch and put in about
a half gallon of dairy milkstone remover, a strong solution of
phosphoric acid that I get at Tractor Supply.  This eats off all the
calcium buildup without harming the base metals.

My little range-top distiller is a batch unit.  Fill it with water,
place it on the stove and let it run.  Check it occasionally so as not
to boil it dry and fuse the crud to the pan.  Dump out the residue at
the end of the run.

>I know what you mean about PA well water.  My mother in law lived
>north of Butler PA and the water smelled of rotten eggs (Ugh).  The
>water also stained every fixture in the house.

In the Middletown/Royalton area, the stuff was so bad that it ate
through the rigid copper tubing the apartment building had been
re-plumbed with right before I bought it.  I never got around to
checking the pH but I bet it had to be at least as acid as vinegar to
have eaten copper like that.

The first day we owned the place, while we were moving into our unit,
wifey made a pitcher of Iced Tea.  In just a few minutes a crap-brown
colored sludge formed and settled to the bottom of the pitcher to
about an inch of depth.  The rest of the tea looked like it had cream
in it.  I asked the neighbor what they did for drinking water.  They
pointed to the metal box on their porch where the bottled water guy
left the water each week.  A buck a half gallon!  I did that for about
a week until I could find a still.


From: John De Armond
Newsgroups: rec.outdoors.rv-travel
Subject: Re: Water filtering for a RV
Date: Mon, 26 Sep 2005 03:19:19 -0400
Message-ID: <>

On Sun, 25 Sep 2005 09:35:56 -0600, Albert <>

>As I pointed out in another post close to a year ago the reverse
>osmosis process does remove "all" dissolved minerals.
>Demineralized water presents a problem in that when it comes in
>contact with a solid mineral it leeches it and absorbs that mineral.
>And that includes your teeth. On top of that our bodies need the
>natural minerals found in most waters.

Utter rubbish.  Compare the amount of "minerals" in a glass of high
quality drinking water to that in even a pinch of most any common food
and get back to me.

>When we constructed any new piping or vessels in our gasoline plants
>there is a problem of what we called dill-berries (droplets of metal)
>that form inside the pipes being welded and if left their they would
>accumulate in pockets due to flow and cause obstructions.  We used
>demineralized water and circulated it through the system usually for
>about three days and it dissolved the iron droplets.

No it doesn't.  If anything is loosened by demin water it is slag
droplets and scale.  Normally accomplished by a chemical flush
(normally buffered sulfuric acid) followed by demin water.  To claim
that anything would remove steel "drips" and not the steel base metal
of the same composition is daft.

>Normal distillation does not remove all dissolved minerals from water
>therefore it does not present the same problem.  We used an evaporator
>(still) for our boiler feed water but it did not remove all dissolved
>minerals from the water and we still had to treat the boilers with
>chemicals to keep the bolder tubes from plating.

The chemical additives are there to prevent dissolved oxygen induced
corrosion and the leeching of minor constituents of the metal in demin
water.  These chemicals may include hydrazine, ammonia and a variety
of buffers and passivators.  Each vendor's chemical elixir is
different so one can't be more specific than that without knowing

Several nuke plants had to re-learn that boiler feedwater can be too
pure and that corrosion results from said purity.  Initially the goal
was to make water as pure as possible to avoid neutron activating the
impurities as they circulate through the reactor core.  It took
several years to learn that the same sort of water quality control as
is used in fossil plants is necessary in nukes.  The many steam
generator replacements over the past few years were one result.
Another was the corrosion and erosion of reactor components.  Davis
Besse in Oh was probably the worst, with erosion consuming over 12" of
first stainless steel and then carbon steel on the reactor vessel

This, of course, has nothing to do with water quality in an RV.  The
reason a reverse osmosis system is a poor choice for an RV is that it
discards several times the amount of water purified.  Not so much a
problem when hooked to shore water but a major one when one is dry

Short of a still, ion exchange resins provide the best water at the
lowest cost.  It is a widely held but incorrect belief that such
resins discharge sodium ions.  Only the sodium exchange resins used in
water softeners do that.  A cation exchange resin exchanges the
metallic ion (calcium, etc) for a hydronium (hydrogen) ion.  When it
snags an electron it becomes water.  An anion resin exchanges a
hydroxyl (OH) ion for non-metallic ions, things like sulfates.  A
combo of both resins completely cleans up the water.  Chemically pure
water is made first by distillation and then ion exchange polishing.

The throw-away cartridge ion exchange resins are normally of this
type, mixed cation and anion resins.


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