API Stress Zyme contains over 300 million live bacteria per teaspoonful which consumes sludge and reduces aquarium maintenance, keeping your aquarium clean and improving the natural aquarium cycle. Making Stress Zyme bacterial cleaner part of your tank’s regular upkeep routine assures an active biological filter, a cleaner aquarium, healthier fish, and good water quality. API Stress Zyme may be used in both fresh and saltwater aquariums.