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From: John De Armond
Newsgroups: rec.outdoors.rv-travel
Subject: Re: calibrating holding tank, etc readings?
Message-ID: <>
Date: Sun, 07 Apr 2002 04:05:21 -0400

On 5 Apr 2002 14:35:39 -0800, (Jason McDannold) wrote:

>I just purchased a used rv and am new to this whole rving thing.  I
>read in my manual that to calibrate thing that tells me with the push
>of a button how full (or empty) my battery, gray and black tanks, and
>water storage tank is/are I have to fill the tanks and then adjust the
>reading on the meter to full.  So I question is how do I know when my
>gray tank is full.  It's easy to tell when the water tank is full and
>when the black tank is full, or close to full (look down the toilet)
>but I'm confused on the gray one.  Any suggestions will be much
>Thanks in advance.

The short answer is, if you can't see the tank level, guess.  The built-in
indicators that rely on probes stuck in the tank almost never work for long.
Oh, we'll probably have our chemical peddler pop up and claim that his magic
elixir will make them work.  Be sure to have your anti-snake oil guards up.

There is a company whose name escapes me at the moment that makes a system
that involves sticking electrodes on the outside of the tank and detects the
presence of liquid on the other side of the plastic through changes in
capacitance.  I've read good reviews.  OTOH, I saw several of these systems on
Camping World's closeout table with $20 price tags (normally almost $200) the
last time I was in Nashville.  I asked the store manager why they were on the
closeout table. He said they'd had so much trouble with returns for not
working that they dropped the product.

After you've been camping for awhile, you'll usually get a feel for what's in
the tanks.  We have, at least.  If you really do want indication, there are a
couple of solutions.

The simple solution is to fit a sight glass to the tank.  This can be as
simple as a nipple and valve installed in the plumbing upstream of the dump
valve and connected to clear plastic tubing which is run up along side the
tank.  The liquid level in the tank will equal the level in the tube.  The
tube will eventually crud up from congealed grease, soap scum and the like,
whereupon you spend another $2-3 for new tubing.

If you want indication inside the coach, probably the cheapest reliable method
is to attach an industrial microwave level sensor to the top of the tank so
that the microwaves shine through the plastic.  This is standard industry
practice for measuring thick or dirty fluids or solids (grain, powders, etc).
The unit is a small self-contained module that typically is powered and
indicates over a 4-20 ma current loop.  Just hook it and an indicator in
series to the 12 volt supply.  Both analog and digital indicators are
available.  It works by beaming a weak microwave signal in the form of pulses
and measuring the delay on return.  The surface of the liquid reflects the
microwave pulses.  Yes, this is a tiny radar system.  While absolutely
reliable, this is an expensive solution, probably costing oh, $500 total.  If
you're interested, let me know and I can point you to some vendors.

Personally, I'd just learn to guess.  There's no huge consequence to filling
up the gray water tank like there is with the black water.  And if you carry
one of those blue sewage caddys, you can dump into it to free up space even
when you can't otherwise dump.  I got all gung-ho about engineering a reliable
level system on my rig when I first got it.  Fortunately procrastination saved
my bacon again :-)  I got used to guessing and just never got around to making
a change.


From: John De Armond
Newsgroups: rec.outdoors.rv-travel
Subject: Re: grey water
Message-ID: <>
Date: Thu, 19 Jun 2003 20:44:42 -0400

On Thu, 19 Jun 2003 23:23:14 GMT, "Glenn Arden" <>

>I agree with you, but if everyone dumped their grey water on the ground the
>campgrounds would soon become very misquote infested.

(I assume you meant mosquito.)  No it wouldn't.  Soapy water is not at all
hospitable to mosquito larvae.  And unless the CG is paved, there's not enough
water to matter.

Grey water on the ground was the rule when we first started camping in the
60s.  On our pickup camper, the sink drains simply poked through the floor of
the camper and ended at a garden hose male end.  We could run a hose off in
the woods but we rarely bothered.  At the little mountaintop CG where we spent
much of our time, the RVs had maybe 10 feet between the units, almost all
dumped gray water on the ground and no one noticed or cared.

Rules banning grey water on the ground fall in the category with those making
it illegal to use a bar of soap when washing up in a stream.  Sheer lunacy.


From: John De Armond
Newsgroups: rec.outdoors.rv-travel
Subject: Re: Generator or Solar Panels
Date: Fri, 11 Feb 2005 16:22:17 -0500
Message-ID: <>

On Fri, 11 Feb 2005 20:58:39 +0000, Wes Stewart <*n7ws*@> wrote:

>On Fri, 11 Feb 2005 13:42:56 -0600, Bob Giddings <>

>|In truth I don't believe this does any harm.  Certainly no worse than
>|tenters washing their dishes and throwing the water into the weeds,
>|which is something I see all the time.  There may be a slight odor at
>|first.  This water has been kept in a tank, and smells stale.  But
>|within the hour it is indetectable.  As long as there is 30 or 40 feet
>|between the grey dump site and anyone else, there is no harm done.
>|All that is in there is 30 or 40 gallons of water, a little soap, and
>|whatever diluted organic matter comes off my body or the plates after
>|I wipe them with paper towels.

Of course it does no harm.  Man has dumped his "gray water" outside for

>Agreed.  I dump grey water all of the time.  I was in a campground
>some place, I believe a Corps of Engineers CG near Little Rock, and I
>happened to notice a sign in the entrance booth that said something
>like, "Grey water dumping only through a garden hose."
>I inquired as to whether I was reading it right and they said sure
>dumping grey water is fine; they figure the garden hose limitation is
>enough to insure that no one is dumping black water.

I'm stunned at this level of wisdom coming from a government employee.
Simply amazing.

Our first camper, a Holiday Rambler pickup camper, didn't even bother with
a tank.  The sinks simply emptied through the shell.  There was a garden
hose attachment, in case one wanted to conduct the water away from the
camp site.  The shower emptied into the sewer connection downstream of the
black water dump valve.  When not connected to a sewer, the garden hose
fitting on the sewer hose fitting was either left open or a garden hose

The places where we camped the most before we parked the thing in one spot
had sandy soil so all we did was to dig a small hole in the ground under
each drain.  Big enough to catch the surge, it held the water until it
soaked in.  No muss, no fuss and no stink.

Back then (late 60s) dumping places were rare.  Sometimes we'd drive to
our dealer's lot to use his.  Most of the time dad would drive out in the
country down a FS dirt road until a convenient pull-off was found.  I
(with dad supervising, of course) would dig a small pit, large enough to
contain the 20 gallon black tank contents.  He'd dump in that hole and I'd
cover it back up with the dirt I'd removed.

This created a little septic system.  No odor apparent after the dirt is
pushed back in.  More than once I dug up a previously used spot and in
each case I found nothing but black dirt, AKA "biosolids".  More than once
I was "requested" to put the black dirt in a bucket for mom to use in the
flower beds.

In a more rational world I'd probably acknowledge still using this method
but nowadays I'd probably be labeled a terrorist and gunned down by the
EPA Gestapo.

>|With occasional generator use, constant replenishment of fresh water,
>|and casual dumping of grey water, I can stay in the boonies for weeks.
>|The black tank is 40 gallons, and won't fill up for a long, long time.
>|I've never reached the limit, so I don't know how long.  A month?

Pretty much the same here.  When I'm going out for an extended stay, I
pull a small trailer.  I load this with several 30 gallon tanks of water,
extra food and gasoline and plenty of firewood.  Just not enough room in a
20 ft MH for all that.


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