I left a checklist for my parents (dad) when I went to Hawaii for 10 days, it was basically feed food once ever 2-3 days from premeasured cups into both tanks, specifically saying which goes into each tank. Then top of the water if needed, I had two pieces of tape on the sump, one a "fill if it goes below this amount" the other "stop filling at this line.
Well food got fed, and water got topped off on ONE tank (ironically the tank I care less about), I think water splashed around a bit because one of my powerstrips was charred black and partially melted (almost started a fire), over all though everything survived so I can't complain. I did have a check list where I asked him to check each box after doing something... well I have the feeling he just checked the boxes before he left without actually doing.
What I'll probably do in the future is move heaters inside the tank, that way if the sump does run dry or your return pump fails, you won't have any issues with heating the tank. Hell I could probably get away with shutting off the sump all together and worry about the evaporation in the tank when I get back, but that depends how long you're gone.
