ABSTRACT - In this study, the veridical efficacy of an aquatic disinfectant tablet composed to calcium hypochlo-rite against red sea bream iridovirus (RBIV). A veridical efficacy was determined with the viability of RBIV contactedwith the disinfectant in viral stock cultured in fat head minnow cell line. An aquatic disinfectant tablet and RBIV werereacted on the distilled water (DW), hard water (HW) or organic matter suspension (OM) condition. On DW and HWcondition, RBIV was inactivated with 25,000 fold dilutions of an aquatic disinfectant tablet. With the investigation ofthe antiviral effect of the disinfectant on OM condition, RBIV was inactivated on 22,000 fold dilutions of an aquaticdisinfectant tablet. As an aquatic disinfectant tablet possesses veridical efficacy against RBIV, the disinfectant solutioncan be used to limit the spread of cultured marine fish viral disease.Key words: Aquatic disinfectant tablet, Red sea bream iridovirus, Calcium hypochlorite, Disinfectant efficacy