Detrital particulates, i.e. inorganic and non-living organic material of colloidal size and larger, span ten orders of magnitude in size and are ubiquitous in inland waters. Interactions between plankton and detrital particulates are reciprocal. Release of dissolved organics by living organisms enter the particulate size fraction by flocculation on bubbles or adsorption to inorganic particles. Bacteria benefit from attachment to particles and are agents,in the aggregation of particulates. Nutrients released by decaying plankton can support phytoplankton growth. Potentially toxic compounds adsorb to particulates and then can enter pelagic food webs or sediment. Material egested by zooplankton contributes to the detrital pool which in turn is a food source for zooplankton.