A preventive treatment is intended to prevent infection, and assist in natural therapeutic recovery from disease infection. A number of very dangerous pathogenic strains of bacteria like Aeromonas, Pseudomonas, E. coli, , etc. can cause catastrophic fish losses in ponds. This has created a strong demand for an effective preventive treatment that does not involve antibiotics, disinfectants, or any other sort of chemical products. Preventive treatment does not kill pathogens directly; it helps prevent and restrict their development. If pathogens get the opportunity to proliferate they can infect the least resistant fish. Good water quality reduces stress in fish and therefore reduces the risk of infection. Kusuri Pro-100 is formulated to help reduce harmful water-borne bacteria. Kusuri Pro-100 contains the highest available concentration of natural beneficial bacteria. Every production batch is tested and guaranteed free of pathogens and dangerous chemicals. Kusuri Pro-100 is used as a preventative. The multiplying colonies of beneficial bacteria out-compete harmful strains of pathogens, by consuming the nutrients that they require to survive and develop. Effectively,Kusuri Pro-100 reduces the numbers of pathogens by occupying their “living space” and replacing the harmful bacteria with beneficial ones. Kusuri Pro-100 can be used in any aquatic environment because it is absolutely harmless. It is recommended not to use UV or ozone equipment when starting the application for 1 week, and to aerate the pond.