Yes I expect the Arduino to control the pump...
One digital output.
I'll be recording the temperature with mini-log temperature recorders...
With a what? You don't want the Arduino recording the data?
I'll be using excel to display my results (if that's what you mean by post-processing)
I don't understand what your asking with "Tracking time"
Time according to a wall clock. You mention "7am" in your original post. Do you expect the Arduino to determine when 7:00 AM arrives?
terryking228 ask an important question you skipped...
Will/can the Arduino be connected to a PC to collect or archive data?