Conductivity Saltwater Meters ?

[SteveMM62Reef]

I have a Fluval G3 and one of its features is a Conductivity Meter and Probes. I mainly use it for the Alarm Feature, to alert me if something goes wrong. It is reading low, and slowly getting worse. I wrote to Fluval and they said to use a soft brush, this did nothing for the problem. What do you use to clean your conductive probes, no matter what the brand.is?

 

[blaxsun]

A soft toothbrush.

 

[SteveMM62Reef]

I did the Soft Tooth Brush, no change in the readings. I figure Calcium is building up on the Probes.