I have two nearby that sell ADA, Neptune and AFA. Though Neptunes Aquasoil is more expensive than AFA's since they buy Aquasoil from AFA. They also have lots of wood and rocks.
I know there are some people in Sac, but havent heard of any cool stores there. Monterey Bay Aquarium is really cool. They replicate natural environments, like the kelp forest is actually replicated from the forest that is literally outside the aquarium building. Really cool place to see saltwater fish, just no freshwater besides a small thing for trout.