After spending nearly 2 days reading both from the newsgroups and on
the web, I think I am more confused now then I was when I started. I
will try to keep this post as coherent as possible.

I did a service call on evaporative cooler at a house that was on well
water in Henderson, Colorado. The first thing I noticed, was the unit
itself looked like a giant snowball. I scraped as much of the mineral
deposits away as I could and got the unit started up. White powder
filled the entire house, despite the door, which was nearby being
opened wide. A couple of months later I had to return as the blower
motor had ceased operating. A check of the date code suggested that
it was not even a year old. I suspect it overheated to the lack of an
air entering past the pads, because once again the pads were
completely caked with nearly 2 inches of mineral deposits. At this
point I was convinced that they had a hard water problem. I explain
to them that they needed to get a water softener for not only this
reason that other plumbing issues. Then they told me that theyhad
been previously advised by both the previous owner, and also a water
company that they had come in later to test the water (as a
consequence of a foul odor in the water), that the water was very
soft. Well, this went against everything I knew. I always thought
that any precipitate out of water was necessarily minerals, and
therefore constituted hard water. Now, I just had a conversation with
them where they did have another water treatment company come out and
check the situation. Again, they were told that their water was "too
soft". They recommended a reverse osmosis system at a cost of nearly
$9,000 and likely $1500 a year additional for maintenance. And again
I was left scratching my head as I have not found anything on the web
or in the newsgroups where I could verify that this deposit as
anything that could come from soft water. Curious, I called another
water company and explained to them what up to this point has been
related to me. That gentleman seemed to be quite confident that what
I was seeing was sulfur. He also said that even if they had installed
a reverse osmosis system, they would still have to install some sort
of system to pre-treat the water for the sulfur. In fact, he
recommended a chloride cycle dealkylizer. That confuses me even more
as I've always associated alkaline and alkalinity with hard water. I
mean, am I wrong, if something is basic it is alkaline and hard, and
if something is acid it is soft?

So, after all this rambling. I guess my first question would be, has
anybody even heard of such a thing, that is, an evaporative cooler
with heavy mineral build up that actually comes from soft water?
Also, does anybody want to toss in their two cents on how to best (and
that would include cost effectiveness) remedy this situation. Other
information that may be helpful is the fact that they have a boiler
(not steam) and a septic system. Any help would be appreciated.
Thank you in advance.