Here's the link for finding a distributor near you.
http://www.3m.com/product/informatio...Aggregate.html!
Click on the link for Colorquartz Aggregate and then follow the Where To Buy link at the top right of the next page.
The T-grade black is the one you want. It should be about $25.00-$30.00 for a 50 lb. bag. The color is as dark or darker than Aquasoil Amazonia and it won't get blown around in the filter. This is by far the densest substrate I have used to date and I've used them all.
