@Orca5094 @casportpony
Keep giving him swim time - watch him every moment, ducklings cannot be left alone in water.
It will take some time, maybe weeks, but ducklings can recover from this kind of thing if they get the right kind of help.
We just have to try things and use what works.
Keep him on the brewer's yeast for two or three months, in addition to his regular food, with water, 24/7.
And please give us daily updates if you can, we love reading about ducklings, and this may help someone else, too.