Calibration Confusion

Can anyone answer this question (assume that my Thermapen is correct)

Actual water temperature = 100°

Anova Display reads        = 104°

Do I calibrate up +4°    or  down -4°  ??

There is a lot of confusion even with the chat staff and the email staff and the calibration part of the app REALLY needs to be clarified with a statement like  "if your water is actually cooler than what is displayed on the Anova Precision Cooker, adjust calibration … (UP? DOWN?)