Seaweed meal
 

I was checking into using "water crystals" in my organic garden because being
in Zone 9, we need to retain as much moisture as possible in the soil.

A British company suggested that I use "Seaweed meal", i.e. ground up seaweed,
as this would help retain water in the soil. I see this is being used a lot on
England, but can only find liquid seaweed or kelp here.

Does anyone here have any experience with this stuff? Where can I get some in
the US, prefereably Los Angeles area.
Helen