nope no southdown here only could get quickcrete wich is silicate based and i might as well do a dsb right if im gonna do it i read somewheres you should use aragonite cause the surface of a grain is porus sorta where a silicate grain is kinda slick so you get more bacteria on the aragonite. it is a bit more expensive but imjutst gonna do 60lbs aragamax and then 40lbs live flordia sand from this site. the sand calculater said i would need 110lbs sand for 4inch bed but i figure with the rock being on the glass it should need less sand so i should be close to 4.i just wanted to make sure the aragamax grain size was the right size