Pendulum Demand Feeder?

[Acer]

I just remembered the pendulum feeder I saw when I visited a fish hatchery this summer. It is essentially a hopper with a hole at the bottom. A rod goes through the hole and prevents the food from falling down... unless it is jiggled by a fish on the other end.

I had never seen that before, and was wondering if anyone has used one or made one? It would be interesting to just see how fast the fish would catch on... although I wouldn't trust my goldfish with one

 

[ChannelCat]

looks cool. Ive never seen that, but my tank would be a disaster. My fish run into everything else, i know they would hit that.

 

[cjohll]

You would end up with some fat fish.