Web alarm clock for 4:29 p.m.
You are halfway through another task when you need a sharp reminder to break away and switch the pump back on after the scheduled power interruption. Set the alarm for 4:29 pm so the job does not slip while your attention is elsewhere. That leaves the pump running again well before 5:00 pm, with time to check that everything has restarted normally.
Because the pump is the reason for this reminder, make sure the alert will reach you rather than disappearing into headphones you forgot were connected. Check the sound destination and volume, then leave this page active while you continue working nearby. If the browser is closed or the phone or computer goes to sleep, the pump alert will not sound, so use a separate phone alarm when you may step away or lock the screen.
Before returning to your afternoon work, place water within reach and have a small merienda only if it will not distract from checking the pump. A quick banana, pandesal, or a few crackers fits the pause better than a full meal at 4:29 pm. Save heavier food for after the restart check, when you can sit down without dividing your attention between eating and the equipment.