I'm constructing an automatic feed like this http://www.fowlvisions.com/?p=633 and I'm thinking about a similar one with an air tight cap for water. Does anyone have anything else similar? I want it to extend out the top of my run (only 4 feet tall) and I would like to be able to keep it from freezing in winter (I had thought of double walled with insulation of some for between the two). Oh and of course I'd like to do it all for less than the $20 a galvanized waterer would cost. Impossible? I think not.