If you give them MEDICATED FEED, then they do not need it in their water, you only give Amprolium either in the water, or the feed, otherwise, you are overmedicating.
Amprolium is the medication that kills off the "cocci"........it is found in many forms, one of which is the name brand "Corid"
Corid is Amprolium, and there is amny more.
And the Medication in "Medicated Feed" IS AMPROLIUM......so please make sure you are doing either or...and not giving BOTH MEDICATED FEED AND MEDICATED WATER............thanks.