Thank you so much! Yes, they can get away from the heat if they need to. And the kale was organic and very clean. The duckling that was worrying me is eating again now, and she seems much better. Maybe she just had something stuck that was irritating her? Is that possible? I might have been overreacting, but I love them dearly already and would hate to have anything happen to one of them. I got the temp down to about 85, too, and they all seem a little happier. I know that I don't need to let them swim everyday, but they really enjoy it and tend to get restless after a several hours in the brooder. I do dry them off really well when I take them out though, and the water is always warm.
Thank you for your help! I think she'll be all right, but I will definitely keep all this in mind just in case. And I think I'll invest in some vitamins and brewers yeast, too.