One thing I learned the hard way, is not to add anything into the tank the week before you go away. I bought a fathead anthias, 3 days before I left for a 3 day weekend. He was fine for the 3 days before I left, and died during the 3 days I was away. He was pretty decompsed by the time I returned. Could have been worse, but I lost a small 2 headed hammer coral, 4 heads out of the 7 on my frogspawn, a small Xenia, and my firefish must not have been happy with the water conditions and committed suicide and jumped out. (had him for about 6 months before that). A lot of other corals looked pretty poor, but the rest, thank God, recovered.
I go away a lot for 2 or 3 days and I don't worry about food. Just feed them well the morning I leave, and when I get back. My auto top-off resevoir is built into my sump and is a little over 4 gallons, so that's enough for a 3 day weekend.
For a week, I set up a large rubbermade to use as a top-off container, and pull the pump from the built in auto-topoff reservoir in my sump and place it in the rubbermade. I use a autofeeder, but I have a possum wrasse and now a longnose hawkfish that don't eat flake, pellets or freeze dried cyclopese. Hopefully they finds some pods to eat. I do have someone come in twice during the week, just to visually check that everything is ok, and feed some frozen food. I portion out the frozen food so that they don't over-feed. I put enough food for one day onto a small tupperware lid, and place the lid into a ziplock back in the freezer, and then hide the rest of the food. They are instructed to thaw and just toss in the food from ONE tupperware cover.
I ask them to leave a voicemail on my cell phone to let me know if everything looks ok.
I also have a heater and a powerhead on a UBS, and have the following batter operated airpump, in case of a power outage while I'm away. It runs off of two D batteries, and will at least put some air into the tank, if the UBS runs out of juice. I have a lot more room on the UBS for more items, but I want it to last the longest for the heat and a powerhead, so I don't plug in the skimmer, or lights, or backup heater and second powerhead.
http://www.drsfostersmith.com/Produ...Ntk=All&N=2004&Ntt=battery operated pump&Np=1