Personally, i think 10 days is too long-they will be nipping at each other, and if a weak one gets a part of its fin nipped off, the frenzy will be on. I would try to feed them as much as possible right before you leave, then thrown in a dozen small feeders, and 50 guppies. The best thing to do is have someone come in once and give them feeders or a bunch of pellets. You never know with those auto feeders, don't buy it right before your trip, you should have the auto feeder going for a few weeks while you are at home.