Archived posting to the Leica Users Group, 2001/01/30
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William Gower jotted down the following:
> You've gotten allot of Alchemy regarding your Watermarks. Now it's some time
> for some Chemistry.
Alright!! Hard Fact kicks Anectodal Evidence's butt!
> You happen to be blessed twice. Not only are you living in Columbus Ohio,
> but also you happen to be drinking water out of the Upper Scioto watershed.
Eh, if you think that I'm drinking the chlorinated crap that comes out of
our taps, you're very, very mistaken. Except for tea. Oddly enough, the
worse the water, the better the tea. Tea in Columbus is just fabulous. But
anything I drink otherwise gets filtered through a Brita filter first.
According to the Department of Public Utilities's Division of Water (DOW)
web site, the DOW initially pumped water from the Scioto River, 125 years
ago. I don't know if they still do, but it smells like they might. Again,
according to their web site, they employ screening and initial sedimentation
(whatever that is), something that apparently isn't needed with ground
water, which would imply that Columbus's water source is something other
than that.
Aha -- 85% is an underground water supply between the Scioto River and Big
Walnut Creek, the remaining 15% from wells. Which would appear to
contradict what they stated above... Oh well.
> Looking at the geology of Ohio, I would take a hydrogeoloical stab and say
> that if the city of Columbus is drawing water from a groundwater Aquifer,
> then it's going to be of Silurian-Devonian genesis, possibly Mississipian,
> maybe a mix from both.
Yeah. Right. Must be. (What did he just say!?)
> Look at your taps. Do you have white scale forming around your faucet? Do
> you notice that the hot water tap has more scale than the cold water tap?
I've only got the one tap, eh, faucet, but yeah, there's some white stuff
around it, but not very much.
> This is Calcium Carbonate. Unlike most minerals, the solubility actually
> decreases with temperature. Calcium is the principal constituent of
> "Hardness". Magnesium is the second. Iron is tertiary. You probably have all
> three.
OK. I apparently also get chlorine ("to disinfect the water") and flouride
("to protect teeth") plus a "corrosion inhibitor" (unnamed) according to the
same website.
BTW -- it's at: http://columbuswater.com/process.htm
> Now go look at the heating element of your electric Kettle.
Nah, can't afford such luxuries. I have the old version, you fill it with
water and stick it on the gas stove ;)
> Water classified as "hard" forms a scum or precipitate in the presence of
> soaps. Photoflo is a fancy soap = hard water will form a scum or
> precipitate in the presence of Photoflo.
Is that what I have on my negs? It's a white residue, drop shaped.
Sometimes you can brush it off, most of the time it seems to have bonded to
the film. The stuff I have is almost uniformally on the base side of the
film.
> If you are so inclined (or any LUG'er for that matter) I can help you build
> your very own water deionizer for a few bucks that will put this issue
> behind you.
Sounds interesting. What're the details?
> William Gower
William, thank you, thank you, thank you, for a great read, some real
information, and for providing some of the behind-the-scenes facts!
M.
- --
Martin Howard | "And many photographers will also appreciate
Visiting Scholar, CSEL, OSU | the separate control rings for focus and
email: howard.390@osu.edu | aperture." -- Leica lens ad copy.
www: http://mvhoward.i.am/ +--------------------------------------------