For instance I have bought Marine Phytoplankton (which are ocean minerals) from one company and then I bought one from David Wolfe (he's a well known raw food guy) and the difference was like night and day. David Wolfe's product was literally about 90-95% more potent than the other company.
So from my experiance marine phytoplankton is the best for ocean minerals, it contains 92 minerals with very little salt, all the minerals are organic and very bio-available.