I've envied those of you who use it as a substrate time to try and get some of my own. I was looking at homedepot.com which has Black Bull 80 Grit Garnet Sand which I think should work because at 80 grit the sand should be about .201 mm(201 µm) which is between the average size I see of many aquarium sands which range between sizes of .1 mm and .4 mm. Is my assumption correct or are those of you who are using Garnet sand using a different brand and size and if so can you please let me know what you're using? Also can you let me know how abrasive it is in comparison to regular aquarium sand?