I have 13 various chicks ranging from 3 weeks old to 3 days old. Everyone seems to be doing absolutely fantastic excepet for one little Plymouth Barred Rock chick named "Little" who is 1 week old. I got little with her sister a week ago, and her sister is lively and happy but Little seems tired and has dark brown poo that is too wet. Part of it holds its shape but the other part is goopy. She eats and drinks, but other than that just stands under the heat. I am feeding them medicated chick starter/grower. I change their water twice daily. I clean their bedding every morning. The red heat lamp is on in their extra large brooder box and under the light its about 98 degrees. The box is about 4 1/2 X 3' so they have plenty of room to get the correct temperature. Can I open up a probiotic capsule into their water? Any ideas?