Any issue adding alive sand to an established reef tank?
http://www.petco.com/product/121742...aspx?CoreCat=MM_FishSupplies_GravelSubstrates
http://www.petco.com/product/121742...aspx?CoreCat=MM_FishSupplies_GravelSubstrates
It's hard to say. How big is your tank? But to be safe, I would do only 10% at a time. The dust cloud alone would prevent me from pouring too much into the tank.
Did you get this at the deal I posted? I got 3 bags for $17 each.