Preventive methods can be incorporated to keep the amount of stress encountered by the fish to a minimum. Additional calcium chloride is not needed in harder waters. In spite of the best preventive efforts, diseases occur. It is vital to detect the disease as soon as possible. The best way to detect a disease at its onset is by observing the fish when they are feeding.
Records indicate the trend of the disease and provide clues as to the cause.
A diagnostic laboratory can use this information to help distinguish between an infectious disease and other types of disease. Days Figure 3. Graphic illustration of fish mortality patterns. Line A represents a die-off resulting from a severe environmental problem such as oxygen depletions. Line B is a die-off due to severe disease outbreaks such as bacterial infections.