Automatic Duck Drinker. This drinker has a float which allows a garden hose to be attached, plus a bung for easier cleaning, and legs
The drinker holds about 16 litres and holes on the side for ducks to stick their heads in to drink. Some pigeon owners are using this as well--without the legs.
The legs are removable and the rubber bung allows easy cleaning out. Comes with a float and fittings which regular garden hose attachment to click on, you supply the hose and click on attachment which usually come with a hose or is easily available.
Consider these for Geese as well. Chooks will use them, their intent is for ducks though.
These where trialed in Australia a while back with some alterations made before we have listed them.