Actually, it’s not quite as bad as that: I have prepared zip-lock bags of food (one per day), instructed the neighbours on how to check the equipment and left them contact details for a fellow fishkeeper, in case anything looks wrong.
The idea is simple: every day, the kids come over and (while being supervised by the parents) feed one bag of food to the fish per day. At worst, the fish are getting fed the right amount of food and the equipment gets checked for malfunctions; at best, the child from a pet-free home learns about the basic responsibility of keeping pets.
Then, once per week, a fellow fishkeeper will come to do a 5% water change and check on the general welfare of the animals.
And just for the fun of it, I am also setting up a webcam, so that I may be able to check up on the fish myself.