Check the listing for details. API Stress Zyme Plus Bio Filtration Booster for aquarium. Condition: New. Listed at 5.99 USD. DescriptionAPI 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 maintenanceImproves bio filter at startupMade in the USAGreat for fresh or saltwaterAPI Stress Zyme Plus breaks down organic compounds that can cause dangerous conditions such as ammonia and nitrite poisoning and low oxygen levels.A continuing use of Stress Zyme will assure an active biological filter, cleaner aquarium, healthier fish, and an overall good water quality. You do not have to keep this product refrigerated. StressZyme can be used in Fresh or Saltwater aquariums and when setting up or maintaining aquarium. Additional features:Contains live bacteria to consume sludgeReduces aquarium maintenanceAdds beneficial bacteria for a healthy aquariumAll natural ingredientsWhen To Use: Use weekly for a healthy, clean aquarium and to maintain a strong biological filter.Directions: Shake well. To maintain a clean, healthy aquarium: add 1 tsp. (5 ml) per 10 US gallons (38 L) or 1/2 cup (120 ml) for each 240 US gallons (912 ml) of water weekly. For new aquariums to help boost the biological filter: double the dose, use at startup and for 2 additional weeks.Dosage:1 oz treats 60 gallons4 oz treats 236 gallons8 oz treats 480 gallons16 oz treats 960 gallons64 oz treats 3,786 gallons4 gallons treats 30,240 gallons