Planted Tank Guru
Join Date: Jan 2010
Location: Contra Costa CA
Try American Soil and Stone in Richmond. Also have a store in San Rafael, but I have not been there.
Best selection of rock in the SF Bay Area.
Morgan's Masonry- stores in Antioch, San Ramon, Tracy
LH Voss- Dublin
Peninsula Building Materials- stores in the South Bay, Livermore
Broadmore- South San Francisco
Mt. Diablo Landscape- Concord
Other stores: Google words like
Landscape, Bulk, Stone, Brick, Masonry, Bark, Soil, Rock
and other terms. I know there are a lot more stores in the South Bay, and the North Bay. I am most familiar with Contra Costa County, so have listed the stores that are local to me.
Most of these stores will sell by the pound, by the bag and by the truckload. Each store will have something different, so you may have to make a day or more for shopping. I would definitely start with American Soils, though. Well, probably visit the stores nearest to you first, then American Soils. Have a look at the displays at American Soils, too. They have some incredible rock, fountains, containers, walls and other garden/landscape things with many, many kinds of rock.
Pricing at any of these will be a lot cheaper than any aquarium store.
Perhaps 10 cents to 25 cents per pound for most of the rock. (I buy it by the ton, and anything over about 700/ton is expensive rock)