This is an instructable about how to make an automatic fish feeder( my version feeds the fish every six seconds to show its working but you can modify the code to make it feed after a few hours or a day). Hope you like it!!
links to the videos:
1. Fish food case
2. Servo motors (x 2 but you can also use one by eliminating the bottom servo)
3. Strips of tape
4. An old plastic Box
5. Some card shaped like a pan open at one end.
6. An Ardiuno and connection wire
7. Breadboard ( optional but I recommend it)
8. Scissors( or knife to cut plastic box)