I've built several gravity feeders, recently, since I had to be away for a couple of weeks, and the lady tending everything told me that my 50 chickens went through about 70 lb. of feed, in five days....I knew I had to do something. After some research, I settled on a Moultrie 30 gallon feeder. It can feed up to six times a day, and has a run time from 0 - 20 seconds, dispensing about 1lb. every 5 seconds...It cost $200 at the local sporting goods/ hunting supply store. It broadcasts about a 20' diameter. It runs on a 6 volt battery, and gives you a readout on the remaining charge. I think I'm going to be happy with it.