unri.ac.id Abstract Multi-cell probiotic containing bacteria Nitrosomonas sp., Nitrobacter sp., and Bacillus sp.. This research was conducted from March to May 2021 at the Fish Disease and Parasite Laboratory, Department of Aquaculture, Faculty of Fisheries and Marine, Riau University. This study aimed to analyze the hematology of tropical catfish and to obtain the best time interval for a…