Removing suspended solids, including uneaten feed and feces, is the crucial water treatment process for maintaining the stable operation in recirculating aquaculture system (RAS). The accumulating of fine particles in recirculating water is unavoidable. It has been a main bottleneck for the fast development of RAS. Considering the low efficiency of foam fractionation, the bubble distribution of aeration and venturi jet were studied. Results showed that both for aeration and venturi jet, with the increase of water salinity, the Sauter mean diameter (SMD) was decreased and the gas holdup was increased. With the decrease of air inflow, the SMD and gas holdup were decreased. In general, the SMD of aeration was larger than that of venturi jet. The analysis of relevant flotation theories revealed that the key factor of foam fractionation for fine particle was bubble-particle collision probability mainly depended on the bubble diameter and particle size. The surfactant was basic condition, and it affected bubble-particle adhesion probability, foamability and foam stability. However, the surfactant, as well as the size of fine particles, was uncontrolled in RAS. It suggested that bubble characteristics may be the leading factor for the foam fractionation of fine particles. In addition, bubbles with different diameters showed different removal effects of fine particles. Then, an integrated foam fractionation of the synergy between aeration and venturi jet was therefore proposed. The gas holdup could reach 0.100 (aeration and venturi jet alone were 0.031 and 0.074, respectively), and the removal efficiency of fine particles could reach 55.84% under experimental conditions (aeration and venturi jet alone were 19.06% and 39.67%, respectively). The aeration-based foam fractionation had a good effect on the removal of fine particles which were smaller than 50μm. The venturi jet-based foam fractionation probably led to the breakup of relatively large particles, and the increasement of fine particles that were 2~30μm. Nevertheless, the integrated foam fractionation could avoid energy consumption and generally reduce the amounts of fine particles that were 2~15μm produced by venturi jet. As a consequence, the integrated foam fractionator can be designed and applied to the management of fine particles in actual RAS.