Been doing this for so long, I have done most of the things mentioned.
Left the water maker running when going out, despite putting a note on the door to turn it off.
Cranked the skimmer up just before leaving. This was pre-waste collector.
Not understanding the relationship of the alkaline well water and ro with no di resin and the higher levels of alk. in some salt mixes. Took a couple years and several lighting/tank combo,s to figure this one out, despite all my experience.
Scratching my new starfire 180 cube before water was even in.
Sigh, I could go on.