Sequencing. Why press multiple buttons to do something when you can do one? With a controller, you could slow the pumps to a slow crawl, shut off the return and skimmer, then turn on return and pumps but wait 5 extra minutes before skimmer comes back on all with one button press. Or have 1 button maintenance modes or special modes for coral acclimation or feeding.
Sent from my SM-G965U using
MASC mobile app