I have 2 6 week old chicks that are less active and are more sleepy and lethargic. I have given them sugar water to pep them up and they seem better but then a day later they are back to lethargic. Should I add vitamins to the water? Everyone else is fine and will the rest be ok with the extra vitamins? I also have 2 call ducks that share the coop will they be able to have the vitamin water? Or could something else be the issue with these 2 chicks? The poop seems normal and I see them eating.