[Mcdaphnia]

Food rots and produces amonnia right?
Couldn' you add amonia to start(maybe a small amount of food)
and have an auto feed add food, which will rot over time, releasing amonnia.

How about adding a turtle, which will periodically and dependably contribute ammonia to the tank water? If the tank contains decorations or equipment the turtle can destroy or use to climb out of the tank, go back to Plan A the automatic fish food feeder. There are also dosers popular with reef people for adding trace elements that you could use to dose ammonia at any rate you desire. In fact some can be tied in with electronic test devices that can monitor the ammonia and the doser will maintain it at the level you choose. Some can even call you and let you know what is happening and ask for new instructions.