At 05:03 PM 5/17/2009, Richard A Jones wrote:
>It appears to be a conductivity problem.  Boulder water is
>pretty pure and soft--not many minerals in it besides some
>rust.

Yup.  Give all the electrodes a good scrub with steel wool -- if that
doesn't do it then a bit of salt is your answer.  I suspect you won't
need a full teaspoon.  Or you can modify the panel by adding a
resistor -- see the schematic at
<http://pws.prserv.net/synergy/Vanagon/H2O_schematic.gif>.

>But what goes on in that flat, black, surface-mounted box
>that the probes connect to?  Could it be something there.

It's just a bunch of resistors.  Nothing likely to go wrong.

  --
David Beierl - Providence RI USA -- http://pws.prserv.net/synergy/Vanagon/
'89 Po' White Star "Scamp"