If the chicks are vigorous and eating well, don't worry about the poop. Actually their poop is a mixture of that and pee. You'll notice chickens don't pee; they just have watery poop. It should be a mixture of part that somewhat holds its shape and part that is plain old watery, but never clear. And for the size of the little guys, they poop a lot and make quiet a mess. I put mine on straw and dump out the box into my garden about once a week and start over. If they were in the barnyard with a hen, their lives would not be nearly this clean.
