Can you please explain the similarities/differences between the liquid plankton and the powdered plankton. The liquid is prohibitively expensive.
Dried plankton would be more stable. The moisture in liquid plankton would promote oxidation of some nutrients present. Most water-based liquid products also require preservatives to keep them molding. Many common preservatives are toxic.
You might also want to take a look at this old post I did on phytoplankton: