Brightwell Aquatics PhytoChrom 500ml 1 - 30µm Phytoplankton Suspension for Soft Corals, Clams, Sponges, and Other Filter-Feeders Overview Provides 6 types of phytoplankton ranging in size from1 - 30µm. Ideally-sized for many soft corals, clams, sponges, tunicates, tube worms, bryozoans, larval crustaceans, and juvenile...