today while at the big B i looked into richgro aquatic soil, i bought a bag to see what it was like as there was one with a hole in it and i took a peek and it looked exactly like diatomite. anyways i got home and opened up the bag and used it to pot a tree up with, it looked like diatomite, i picked a larger piece up and snapped it in half, it felt like diatomite, the i wet it, and it come up very similar to diatomite aswell, the only difference is it was a little whiter than the diatomite i got from up here, maybe it is a Mt. silivia, i havent used that one, if someone has a pic of mt. silvia that would be great.
there was also a couple of other different looking pieces, they were dark some black i was thinking it moght be charcoal but am unsure. i am going to be emailing them to see if they will tell me the contents.
here is a link to there site
http://www.richgro.com.au/index.php
if anyone else has used it please let me know

jamie
