AWOL:
All doable and feasible, but ask yourself: do you want to trust your fish to your programming skills?
All of these parameters are information that is handy to know. Because this doesn't control anything, rather tells you information, in my eyes you are still better of with this thing rather than not knowing this info at all.
Would it be possible to have 3 LEDs attached, with a reset button as well? Eventually all I would like to be able to see would be the 4 arrows, reset button and 3 LEDs.
Green: Working
Orange: Error
Red: Alarm