I have used the small packs of probiotics for my ducks (one pack only fills 1 gallon and I'm using two five gallon heated waterers right now), but I need to find something with a larger amount. I was wondering if anyone has used Probios for their ducks. I know it says it is okay for birds, but I know that waterfowl may require different things. I was looking aroind on various websites and it says it is okay for chickens and turkies but it doesn't say anything about ducks. Any advice or feedback? Or has anyone found something else that works better? Thanks.