So I bought this unit used, and the owner before decided to put water in the cap at the end of the probe. When I look at the body of the probe, I see dark water inside.. Is it supposed to be water proof? Could this be why my readings are incorrect? I did attempt a calibration with 7 and 10 solution, but it never did hit 10 and sat around 8.6. Kinda sounds like I may need a new probe unless someone else can chime in.
