Got these plasson drinkers for my poultry operation in The Bahamas and these are my best investment along with the other stuff I got from Hog Slat Tried the nipple thing but they wasted too much water and they went bad and keep the coop wet. I have them on a gravity feed set up and not a problem. Saves time, energy and water. Thank you Hog Slat and Cameron who helped me along the way. Green Acres Apiary and Poultry Farm