Well there you have it hi-revs, nuts, crackers and beef jerky should take care of your tank while you're away. Seriously though, if it were my tank I would leave the lights off and have that relative stop by once a week just to throw some food in. No wcs unless its by someone you really trust, otherwise it'll probably cause more harm than good after you do that one big WC before you leave. You'll have the peace of mind knowing someone is stopping by that will notice anything major (power outages, leaks, etc) and that the fish won't be wasting away without food (not that they would necessarily, just the peace of mind). I also believe that running a fraction of the feeding is better than none at all during longer vacations since its less of a shock to your fish and their metabolism and the tanks biological filtration (ie: maintaining more consistent bacteria levels by avoiding sharp depletions and spikes in nutrient levels).