Fish can easily go a week without food.
I would take a small container, fill it with food, and i struct someone to poor it into the tank halfway through your vacation. Whatever you pit in the container should be a normal size meal. Don't add extras. Make sure that the person who dumps it in the tank doesn't add anything more.
They should be fine being fed 1 time in 2 weeks. But if you're nervous, leave out 2-3 containers and tell people to feed one container on a day, another container a few days later, and another a few days after that.
I wouldn't leave the fish a full 2 and 1/2 weeks without food.
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