Abstract: A fish feeder which utilizes water to fill a water container to induce a rotational movement in a rotatable arm. A predetermined rotation of the water container causes the water container to dump its contents and cause a rotation of the rotatable arm in an opposite direction. Abrupt halting of the rotational movement of the rotatable arm induces a vibrational movement to cause fish feed to be dispensed from a feed pan. The amount of fish feed dispensed for a wide range of grain sizes is provided in the present invention in addition to a precise control of the frequency at which food can be dispensed.