Yeah i figure anything can the beardie can swallow could possibly be dangerous. So i know the play sand isnt 100% harmless. I was just told that play sand would be a safer alternative due to the sand grains being round and not jagged. And yes all the rocks are sifted out of the sand, theres nothing in his sand but the sand grains themselves now. Oh yeah and i had him on the calci sand and cleaned his poop out every morning. For some reason he poops late at night when im sleeping, and his room smells like poop every damn morning, LoL...He's a healthy one now and my gf likes to call him Fatty. I just wanted to make sure that changing from calci sand to play sand wasnt a complete waist of my sifting time. He seems to have taken to it very well. And honestly i dont know how he has lasted all these years without the proper care...Honestly u just wouldnt imagine how much of a different beardie he is now compared to when i first got him. Lucky him he came to a good home.