I have 12 baby chicks that I hatched myself, they were doing fine but now some have very runny poo. I have even had a couple get pasty butts, but I don't understand why. They hatched this weekend and I have been cleaning their water twice aday and cleaning their cage while they were on paper towels about 4 times aday. I put them on shavings just a little bit ago because it was getting too much with the paper towels. What should I do for them?