one huge advantage of using a ph probe, they aren't fooled by water
coloration which happens to be a real problem with my tap water used in
the hot tub.  the test strips never show the real ph, and just look
wrong.  i got a $50 ph probe from a chemical catalog and it works great.
 they say to calibrate before each use, but that's for maximum accuracy,
for hot tub use i only check calibration every few months as long as it
thinks the buffer it's stored in is still about ph 7. =20

if they do get dirty or otherwise act up you can clean them in alcohol
and water and soak them in super saturated potassium chloride for
awhile.  i use "no salt" salt substitute, just put more in a small
container than will dissolve, after a couple of hours soaking it's ready
to be recalibrated and good as new.  i've used it for over 2 years and
just had to replace the battery.  it's now paid for itself as a
replacement for test strips that are now only used to check bromine
level (and that isn't checked as often as ph and you don't adjust it in
small steps and have to remeasure like with ph).  definitely, if you are
going to measure ph often get a cheap scientific model ph tester.  mine
goes from 2 to 12 or 13, i forget but it's about as large a range as
normally needed for nearly anything.  i got a pint size container of ph
7 and ph 10 buffer for calibration and both are still more than half
full, i think they were $10 ea., not a problem.  you can also look up
how to make your own buffer, it's fairly simple.

"Peter L. Peres" wrote:
>=20
> On Fri, 10 Sep 2004, CSB wrote:
>=20
> > They're also used for testing pool water... the range measured isn't
> > great though (6-8 I think)
>=20
> It's exactly what you need. Neutral pH is 7.
-------

--=20
Philip Stortz--"In Germany they came first for the Communists, and I
didn't speak up because I wasn't a Communist.=20
Then they came for the Jews, and I didn't speak up because I wasn't a
Jew.=20
Then they came for the trade unionists, and I didn't speak up because I
wasn't a trade unionist.=20
Then they came for the Catholics, and I didn't speak up because I was a
Protestant.=20
Then they came for me, and by that time no one was left to speak up."
-- Martin Niem=F6ller, 1892-1984 (German Lutheran Pastor), on the Nazi
Holocaust, Congressional Record 14th October 1968 p31636.

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