Putting your probe in a jug of water is fine for a kegerator, but in a fermentation setting, you should be monitoring the temperature of the beer. Fermentation puts off heat, so the beer is likely several degrees warmer than that water. At least, in my very limited experience (first lager ever is in the ferm chamber right now), that's what I've noticed.
Tap 1: English Dark Mild Tap 2: American Brown Tap 3: American Amber Tap 4: Sour Belgian Brown Tap 5: Nitro Milk Stout
Kegged: Amber, Brown, Milk Stout
Lagering: Vienna Lager