I brought four two-day old hatchery chicks home last week, (five days old now) and from the start, one or two have had very watery poo. This isn't the first batch of chicks I've raised, and I haven't experience such watery consistency in poo from youngsters before. They are otherwise normal. Active, eating well, drinking, and sleeping at regular intervals. None appears to be lethargic. They're getting medicated chick starter, and water with vitamins added, with a drop of ACV. Is this something I need to be alarmed about? What can I do about it?