The feeder guys on the forum say that it is important that the fish eat up all of the food that you put in. Otherwise you are just adding very expensive fertilizer to your pond bottom that is going to go to the plants. Once your fish are trained, you need to determine how long it takes them to eat most of the food and set your timer appropriately.
I would also utilize a feeding ring on a lake your size. Especially AFTER they are trained. However, at the start you may want some feed drifting all over the lake? Hopefully, the smart fish will follow the food back to its source.
I don't believe you can feed an entire 19-acre lake from one feeder. However, there are some feeding threads where people have determined that fish will travel a surprisingly long way to the feeders!
Observe your results. If you think you are having a positive effect for the time and money, then you can always add additional feeders at a later date. Plus your learning curve will be higher on the later feeders!
Good luck. And as Sunil says, have fun!
