); [EMAIL_ADDRESS] (J.X. ); [EMAIL_ADDRESS] (M.S. ); [EMAIL_ADDRESS] (Y.L.) Zha Xu  
1 CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; [EMAIL_ADDRESS] (F.C. ); [EMAIL_ADDRESS] (Y.D. ); [EMAIL_ADDRESS] (T.Q. ); [EMAIL_ADDRESS] (L.Z. ); [EMAIL_ADDRESS] (J.X. ); [EMAIL_ADDRESS] (M.S. ); [EMAIL_ADDRESS] (Y.L.) Zianping Sun  
1 CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; [EMAIL_ADDRESS] (F.C. ); [EMAIL_ADDRESS] (Y.D. ); [EMAIL_ADDRESS] (T.Q. ); [EMAIL_ADDRESS] (L.Z. ); [EMAIL_ADDRESS] (J.X. ); [EMAIL_ADDRESS] (M.S. ); [EMAIL_ADDRESS] (Y.L.) [PERSON]  
1 CAS and Shandong Province Key Laboratory of Experimental Marine Biology, Center for Ocean Mega-Science, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; [EMAIL_ADDRESS] (F.C. ); [EMAIL_ADDRESS] (Y.D. ); [EMAIL_ADDRESS] (T.Q. ); [EMAIL_ADDRESS] (L.  
and uses various technologies to carry out physical filtration, biofiltation, and disinfection for water recycling [3]. The core of an RAS is the water treatment system, which mainly includes micro-screen drum filters, biofilters, oxidation devices, and disinfection devices [4]. Suspended solids removal is a critical part of water treatment in the RAS. Suspended solid particles are composed mainly of feces, residual feed, and bacterial flocs [5; 6; 7]. Feed is the main source of suspended solids in the system, and studies have shown that 25% of feed is converted into suspended solids in an RAS [8]. Suspended solid particles have been proven to be the leading cause of high turbidity in aquaculture water, which can cause stress reactions and endanger the health of aquatic animals [9]. As residence time increases, the suspended solids block the breeding facilities and increase chemical oxygen demand. Organic solid waste can be mineralized and decomposed to increase ammonia and nitrite concentrations and increase the load on the nitrification function of the biofilter [10]. Suspended solids removal devices in an RAS can be roughly classified according to the particle size of the suspended matter: sedimentation separation devices, micro-mesh filtration devices, foam fractionators, and ozone generators. The micro-screen drum filter, which is a physical filter device widely used in RAS, has the characteristics of strong adaptability, minimal floor space, and a high level of automation [11]. In a drum filter, the screen is fixed on a rotating drum frame on the horizontal axis and partially submerged in water; water flows into the drum and radially through the straining cloth, which captures fine particles with a suitable mesh size [12]. The micro-screen is the central working part of the drum filter, and the mesh number can directly affect filtration performance. [PERSON] et al. [13] reported that the removal rate of particles larger than 60 \(\upmu\)m by the drum filter could reach more than 68%. [PERSON] et al. [14] found that the removal rate rapidly increased when the mesh number was increased from 150 to 200. The effect was apparent when the screen mesh was 200; the TSS removal rate reached 54.90%. Generally, 200 mesh is the principal mesh size used, as it is the one with the most outstanding technical and economic advantages [11]. A high-power centrifugal pump and an oversized drum filter are generally used to ensure [PERSON] circulation flow and filtration ability in an [PERSON] [15]. The water in a traditional fixed-flow RAS is highly turbid when the breeding animals are fed and when they defecate. However, at other times, the water is relatively clean and does not require high-power pumps to recirculate it, resulting in wasting resources.