I put about an inch in a glass tonight of White sand from Mississippi beaches. This sand comes from past the barrier islands in the gulf. I then poured about 2 inches of white vinagar on top and waited 3 minutes. No reactions took place at all. If this is silica I assume I dont want it in my new tank build. Also I assume no buffering capacity will be acheived with this sand. I think I should just use it since it was free outside the house and obtain a good argonite based sand. All comments appreciated.