...sounds like pool filter sand to me! Its basically just quarried screened and washed sand, not much more to it! I have purchased different brands of pool filter sand and they have had different colors, one a real sandy color and the other a lighter color with dark bits mixed through, they both look good in an aquarium. You can also get different grain sizes if you really want, its rated by the seive size they use.
Back to the question, I used 4 x 25kg bags for my 220g (5'7" x 2'4") and it gave me probably about 1.5" - 2" covering all over, I added laterite under this and river rocks on top so it gave me plenty of substrate. I will post some pics this week hopefully, still setting things up at the moment.