Check the listing for details. API Stress Zyme Bacterial Cleaner Freshwater & Saltwater Aquarium 4-Ounce Bottle. Color: Multi-colored, Condition: New, Made in US. Listed at 12.49 USD. Reduce aquarium maintenance by creating a naturally balanced aquarium with API STRESS ZYME Freshwater and Saltwater Aquarium Cleaning Solution. Fish waste, sludge, uneaten food and other organic compounds can cause harmful water conditions including ammonia and nitrite poisoning and breathing difficulty. They can also be difficult and time-consuming to remove especially from rock, coral and gravel. API STRESS ZYME Freshwater and Saltwater Aquarium Cleaning Solution contains over 300 million live bacteria per teaspoonful to consume sludge and organic debris, keeping gravel and glass clean naturally and boosting the natural aquarium cycle, reducing aquarium maintenance over time.