That should be fine.
Just make sure they are warm enough:
https://www.backyardchickens.com/articles/aarts-chick-heat-blurb.75619/
It doesn't look like coccidiosis to me.
I asked about the other stuff because that can affect their dropping.
Those grains look a bit big for chicks not out where they can get grit.
Is it some kind of starter feed?
Are they going under the light to keep warm?
Is the light you have specifically for poultry?
Some heat lights, used in the food industry, can be covered with a safety coating of teflon which...