Particles not only have direct influences on cultured species, but also affect the efficiency of other water processing elements, thus becoming a restrictive indicator for reuse and discharge of aquaculture water. This paper summarizes descriptive indicators of properties of solids in aquaculture water, analyzes the source of particles during cultivation based on characteristics of aquaculture, and estimates particles necessary to be removed based on water feeding quantity; it also introduces the method to remove residual feeds and excrement from the aquaculture tank with double-rowed pipe as quickly as possible; finally it concludes several common solid-liquid separation techniques. When solid-liquid separation techniques are selected, the size of particles removed, head loss, hydraulic loading and overall removal efficiency, as well as whether it is likely to break particles of large size into particles of small size during removal so that the difficulty in removal is increased on the whole should be considered.