Safety Stop is a simple and effective way to help protect your Saltwater and Freshwater aquarium fish from serious unwanted disease outbreaks caused by external parasites, and bacterial and fungal infections. New fish are often the source of infectious diseases that can wipeout an entire aquarium. Be proactive and give your fish a Safety Stop bath to significantly lower the risk of introducing deadly diseases. Protect your investment!!! While there is no substitute for extended quarantine of new fish in a separate hospital tank, often it is not practical. We recommend using Safety Stop before introducing the new fish into your main aquarium or into the quarantine tank. For multiple tank owners, it should be used anytime a fish is transferred from one tank to another including all quarantine tanks.