## 5 Conclusions  
Aminoclays (ACs) offer an approach to the problem of HAB control. One-pot synthesis and mass production of these materials for control of HABs is feasible [25]. In addition, it has advantages such as optical transparency, superior dispersion, no need for surfactants, and maintained ammonium-like properties. It is suggested that AC is capable of providing effective HAB control in small amounts. In the previous works, especially using MgAC, it has been investigated with selective algicidal activity of redditics in seawater [19] and both in increase of cell size and lipid contents in green microalgal culturing systems. However, in this research, the combination of _Microystis_ cell-free medium and ACs could be considered in controlling cyanobacterial blooms.  
However, further studies are needed in order to comprehensively assess the stimulating/inhibiting properties and potential biological risks of this material [45]. One of the critical challenges is the selective elimination of HABs in environments against other non-harmful phytoplankton. However, there remain a few challenges. Current research demonstrates that the use of individual ACs, combinations of ACs, or further development of multi-functional hybrid clays can improve the efficiency and cost of management and testing for further control of HAB species. If such approaches are likely to harm other resources [46], these ACs can be immobilized on the substrate or mixed with other clays and compounds to reduce this risk. However, this may reduce algicidal activity. In any case, certainly, these approaches can be used to deal with \"tides\" of cyanobacterial blooms as well as membrane-fouling problems [47].  
The following are available online at [[https://www.mdpi.com/article/10.3390/app11125607/s1](https://www.mdpi.com/article/10.3390/app11125607/s1)]([https://www.mdpi.com/article/10.3390/app11125607/s1](https://www.mdpi.com/article/10.3390/app11125607/s1)), Figure S1: Ideal three-dimensional structure of MgAC, reproduced with the permission from reference ([PERSON] et al., 2014)., Figure S2: Optical microscope images of cell lysis of Microcystis sp. KW due to AC (0.1 g/L) loading. It is noted that the white bars are 10 \(\upmu\)m scale. Figure S3: Optical microscope and fluorescent images of cell lysis of Anabaena sp. KVSF7 due to aminoclay (0.1 g/L) loading after (A) 0 day; (B) 2 days; (C) 4 days; (D) 6 days; (E) 8 days; (F) 10 days. It is noted that the white bars are 10 \(\upmu\)m scale., Table S1: Mono-culture and co-culture experimental designs of two cyanobacterial Microcystis and Anabaena species., Table S2: Experimental designs to test the effect of Microcystis sp. KW cell free medium (MSCFM\({}^{\prime}\)) and CaAC on Anabaena sp. KVSF7.  
Study conception and design, data acquisition, analysis, and interpretation, M.K.N., J.-S.K., and Y.-C.L.; drafting, M.K.N. and Y.-C.L.; critical revision for important content, M.K.N., V.K.H.B., C.-Y.A., H.-M.O., J.-Y.M., and Y.-C.L.; final approval of manuscript, M.K.N., V.K.H.B., C.-Y.A., H.-M.O., J.-Y.M., and Y.-C.L. All authors have read and agreed to the published version of the manuscript.  
This research received no external funding.  
Not applicable.  
This work was supported by the Basic Science Research Program through the National Research Foundation of Korea funded by the Ministry of Education (NRF2017R1D1A1A09000642) and by the Basic Science Research Capacity Enhancement Project through the Korea Basic Science Institute (National research Facilities and Equipment Center) grant funded by the Ministry of Education (2019R1A6C1010016).  
The authors declare no conflict of interest.