I use the one pint plastic hang on wire cup. In winter put water in twice a day. I used these to seperate single Birds out in when I was showing a few year ago. This wall has 150 Barrells and I can seperate out over three hundred birds along with the Cages inside the Building. Where I live the Barrells are faced tho the north and that way no rain or snow in them. They are best in a shady area. Will upload the brooder box's
That is extremely interesting to use the barrels for individual birds! I thought perhaps they held food or water but now looking at your pic again I can see the screens on the front. How long do you keep the birds in there for?

