The build-up of organic pollution in the aquarium inhibits the growth of nitrifying bacteria. The bacteria in API Stress Zyme keep conditions in the aquarium right for the development of the biological filter by consuming harmful organic pollutants. This speeds the development of the biological filter in newly set up aquariums. A build-up of organic compounds also promotes the growth of disease-causing organisms in the aquarium. API Stress Zyme keeps the biological filter working properly by keeping the aquarium gravel and filter clean. Water quality and living conditions are improved when it is used on a regular basis. Each teaspoonful contains 300 million bacteria. These bacteria are in a dormant state and become active when added to the aquarium. Stress Zyme has a five year shelf life and does not require refrigeration. It is effective in freshwater and marine aquariums.Image is for illustration purposes.