Phytoplankton Suspension for Soft Corals, Clams, Sponges, and Other Filter-Feeders Provides phytoplankton ranging in size from 4 – 10m. Ideally-sized for many soft corals, clams, sponges, tunicates, tube worms, and larval invertebrates. Formulated to provide over 75-million phytoplankton cells per ml. Does not require refrigeration. Supplemented with a proprietary amino acid to aid in coloration of invertebrates.