I was at Target today and they had a small size dog waterer with a one gallon gravity drip system that goes into a large bowl. I looked it up on line and they also have 5 gallon ones available. Has anyone ever used this and if so, how did it work for you? I'm using large dog bowls right now but I would like to have something even larger to ensure that they never run out. And, yes, I did try the nipple system but my chickens refused it.