I am a new user, so maybe this is a known bug. ( I am using the Aquaero 6 XT and latest software)
I was setting up a virtual temperature sensor using the Temperature Difference mode and found that it works correctly if the temperatures are displayed in degrees Celsius.
However, if the temperatures are displayed in degrees Fahrenheit the result is off by 32 degrees. (76.1 deg F- 75.6 deg F shows up as 32.5 deg F)
Since F=9C/5+32, I'm guessing that the code takes the difference and adds 32 to it.

I found a discussion of this here:


Aquasuite 2012 math error

German engineering at its worst!!!