Advise PLEASE! sick chick possibly?

[Yardfarm Family]

Advise PLEASE! I have 6day old chicks that are all twitching their heads. One started last night and now all are. The one that started first just pooped a runny, slightly pinkish poop. Are they sick?? Can they be sick when they are all running, playing, and eating and drinking well. Should I put more vitamins in their water. I don't know what to do because this is my first time. I am really worried! Could this be Marreks disease?

 

[Izzymoon]

no vitimans in the water, put apple cider vinegar. I assume you are using chick starter and it has all the proteins they need. I have never done anything but chick starter and apple cider vinegar and all my girls are healthy. (6 weeks) Don't over think it, they are all growing feathers and get very itchy and twitchy. try changing the water first and double check how close the heat is, they might be hot.