Do you have a photo of the waterer you use for your chickens and for your ducks? A web link to something similar would work. Honestly, this winter I'm trying to go without heating water. I find it's pretty easy for the ducks (my chickens are in a separate coop/run). With a relatively deep bucket/lager volume of water, it takes longer to freeze. The ducks are in and out of the water so frequently that they are constantly breaking any surface ice and have water access virtually all day even when it's really cold. I would say that in my climate it is below freezing 24 hours a day for several months of the year. I just give the 6 ducks a 3 gallon bucket of fresh water each morning and that's it. I have two buckets, so I keep one bucket in the human house so it's thawed, fill it and bring it outside in the morning for the ducks, grab the nearly empty/frozen water bucket from their run and put it in my human house, by the next morning that bucket is thawed and ready to refill with fresh and I bring it outside and swap them again, so there's always a bucket in my house melting and always one in the run freezing and I can just swap them at any time, usually just once a day for the ducks is sufficient.