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Re: pH meter resuscitation

>Hi again,
>Today I managed to beg borrow + steal two pocket pen pH meters from my
>chemistry department. They have been in the professors desk drawer for
>time and they were pretty dusty and totally dried out (crud all over
>probes). They are small Hanna types - one is the pHep+ and the other
>says pH on it (but is exactly the same design). I know you're not
supposed to
>let Hanna meters dry out, but the pHep+ actually seems to work, I
>it at pH 7.0 and it gave moderately stable readings in my tanks that
were the
>same general area as the pH test kit results. My question is, I
>reading sometime ago about a method for reactivating worn out probes by

>soaking them in a solution of (could have been) KCl. Do those who know,
>that this will be necessary for these meters? And could someone e-mail
>offlist and tell me how they work? I know they use a platinum wire for
>something or other, and on the pHep+, that looks pretty furred up with
>Basically, do you think these meters are beyond salvation? (They better
>be, the cheapest ones I can buy are about $85!!)


I had a Hanna pHep3 probe.  You should do just as Chuck has suggested.
Soak the probe in pH 4 solution for several hours.  Rinse and then store
in pH 7 or saturated KCl solution.  I suggest the KCl solution because
it will not grow algae in it over time, when I used pH 7 solution algae
would grow in the solution.  My Hanna eventually would not calibrate

You can find affordable pH probes at www1.fishersci.com.  I bought a
Corning pH probe with a replaceable probe ($50).  This way if the probe
goes bad you can replace it for $21, instead of buying a whole new unit.