Has anyone here tried the PVC-pipe feeders? I'm thinking of putting these in as the solution to the problem of getting enough feed to the girls, esp. when we are away. I'd hang another feeder, but it's getting a bit crowded in there and the girls have to stay in because of really high winds. I've seen plans for the feeders, but don't recall anything about how many to install. Assuming a 3' length of pipe for each one (the vertical part, anyway), would 3 of them be enough for 12 hens? How long would the feed last?