The name of the sand is New(Old?)Castle, mined by a company in Florida. The sand, as of now and has been, is only available on the East Coast. I did research on this a long time ago, but apparently HD packages the sand under two names for commercial and retail use. I do not remember the other name, sorry. If you live on the East Coast and can find the mining company, you can pull up a pickup and take the sand for free....not bad!
Otherwise, you can go with the usual Caribsea or other brands.