API Stress Zyme PlusAPI Stress Zyme Plus helps improve the development of the biological filter, as well as cleaning a dirty aquarium. API Stress Zyme contains millions of live, beneficial bacteria cultures to break down and destroy sludge in the gravel bed while keeping grass and plants clean. Keeps aquarium clean and reduces maintenance Improves bio filter at startup Made in the USA Great for fresh or saltwater API Stress Zyme Plus breaks down organic compounds that