Oh yeah, I wanted to mention that I read on another garden site that when you use perlite or any other thing like DE and Turface that you should wear a N95 Mask, have you heard that?
I guess DE dust is like thousands of razor blades in your lungs if you breathe it in and the same for the others too.
N95 Particulate Respirator
http://www.lowes.com/pd_69110-98-8210_