My 16 CornishX chicks are 3 weeks old now, and have been on vitamin-supplemented water since the beginning. Should I keep supplementing their water until butcher in another 5 weeks or so, or is it not necessary? They are out in a tractor now on grass/straw as well as eating a 20% poult grower. None show any leg problems and they actually all skitter around like a bunch of pinballs, so I'm guessing they're plenty healthy. Thanks for reading and responding.