Attended a class over the weekend on diseases of poultry taught by a local avian vet. She felt that nipple waterers were best for poultry (including ducks - I specifically asked the question) as there was less disease and it was easier to keep clean. She did note that you still needed to allow them access to deep enough water to clean their nares (term?) and that you had to teach them how to use the nipple waterers. Just curious as to what experience everyone has had using nipple waterers from there ducks? Seems you still have to keep the open water available, so not sure what you really accomplish with nipple waterers.