I use stone sand, its also called manufactured sand. Cost about $6 a ton at the gravel pit and is a great scouce of grit, I am putting in my new coops here is a link to the thread there are a lot of pics, I hope it helps
https://www.backyardchickens.com/forum/viewtopic.php?id=375826
https://www.backyardchickens.com/forum/viewtopic.php?id=375826