Biosolid wastes from RASs carry fecal solids, uneaten food, and detached bacterial flocs.Efficient solid waste removal or reuse in an RAS is required to meet adequate water quality requirements, and many solid removal devices have been developed and tested.In many RASs, whether operated as indoor or outdoor systems, effluent is treated before its final discharge. Such effluent treatment may comprise devices for sludge thickening and sludge digestion as well as those for inorganic phosphate and nitrogen removal.