i like hampster water bottles for my chicks in the rubbermaid brooder box. i am planning on installing a gravity fed system with those little cups that fill with a small amount of water each time the chicken drinks using pvc pipe and a platic 55 gal drum on a wheeled stand as i will be using it for 2 chicken tractors. I will probably paint the drums white. I learned from my uncle who owned a plant nursery that by painting the pots white, the temp dropped 3-4 degrees in the summer and kept the roots of his plants growing. I also plan to wrap the drum with that bubble looking insulation stuff that comes in a roll. the neighbors might think i have a space ship, but oh well. ALSO, if you go to the coop design section of the BYC, i saw a guy that made waterer out of a 5 gal bucket and cut holes in the side, about 6 inches from the bottom all the way around the bucket, and hung it, it looks like it takes up alot of space for a chicken tractor, but all they can fit in is their heads, and they can jump on it all they like and it aint falling down.