I have 5 three week olds' bought at TSC, and 30 "extotics" from Mcmurray. I had them in two brooder boxes in the bathroom, but this weekend my husband built a larger brooder box so that I could integrate the flock early and because they were quickly outgrowing those plastic totes! I am using the sand (mixed with diatomaceous earth and the PDZ as well. We may be asking for advise on the the building of the run very very soon (the coop we ordered as an 8x10 shed to be delivered next week).