Sorry for hijacking a little... Thank you. Experimenting with the pvc just fell far down my priority list. I will stick with my dog-bowl-i -a-weighted-pail as the primary feeder.I had a single pipe one back when I only had 4 birds, so they'd take turns eating, but boy was it messy. The one I had had no real lip to prevent them from billing out feed, and the feed in the tube itself would get damp from morning condensation and start clumping.
A plain old plastic gravity feeder works better for me. A lot less clean up needed, less waste of feed, and because it's more open it doesn't develop condensation like the enclosed PVC one did.