I ran the salinity test using the test buttons on the Aqua Pure 1400 motherboard (with salinity probe disconnected) and got readings of 2.7 for salinity versus the stated 2.8 and 74 degrees versus 73; are these a factor of over all calibration of the board or is the board bad? With salinity probe connected, I am getting readings of 1.3 versus a lab test of 2.9. Thoughts? The salinity probe appears to be clean.