I had seen on here that putting river sand inside works great and stopped by this morning at a company that sells rock,sand, dirt and I ask if they had any river sand and told them what I was planning on doing with it and they didn't have river sand but said she had customers that uses their red sand for the same purpose and was hoping someone could tell me if that would work in place of river sand? I am new to raising chickens and found this site and it is awsome. I have learned so much b y reading what everyone has posted and it has helped me so much. Thanks for any help you may give me.