Planted Tank Guru
Join Date: Jan 2010
Location: Contra Costa CA
Also, call all the masonry yards in your area.
Peninsula Building Supply is a big one, with yards in Livermore and Santa Clara.
There are others. Look for masonry, brick, rock, soil, bark, landscape and related terms.
Is there a Tractor Supply down there? The nearest one I know of is in Dixon or near Petaluma.