It can take chicks quite a while to learn how to roost, mine didn't start until they were 10 weeks, do they have an area where they CAN dustbath? If the soil is too hard, they won't even try. I would keep feeding the electrolytes and grower, nugget could just be a late bloomer ( i have one ) Lock the chicks in the coops for 4-5 days and then let them out, this will help them to learn how to roost, and to go back into the coop at night. Yellow poop is normal. It's a ceacal dropping.
