In the wild, fish can go days, even a couple weeks without food. I've let my fish (tetras cories shrimp snails) go a tad over a week without feeding. Feed them daily, and a bit more than your usual feeding amounts for a week and you'll be fine. Also do a big (like +50%) PWC
right before you leave. Of you were gonna be gone like 2 or 3 weeks, I'd say an good auto feeder and a good friend to do a PWC
would be in order.