Open mobile app


Customer supportTypically replies within a few minutes
Need help with placing an order, delivery, or something else? Start with our Help Page — or message us anytime for support.
Say goodbye to murky water and endless maintenance! API Stress Zyme™ bacterial cleaner is your secret weapon for a thriving, pristine aquarium. This powerful solution contains over 300 million live bacteria per teaspoonful, meticulously selected to consume sludge, reduce organic debris, and radically simplify aquarium upkeep. By keeping your aquarium clean and optimizing the natural nitrogen cycle, Stress Zyme™ ensures a balanced, healthy environment for your fish.
Whether you're setting up a new tank or maintaining an established one, making Stress Zyme™ a regular part of your routine assures an active biological filter, a cleaner aquarium, healthier fish, and consistently good water quality. It's effective in both freshwater and saltwater systems, making it the go-to choice for all aquarists!
API Stress Zyme™ introduces beneficial live bacteria into your aquarium. These bacteria are uniquely suited to consume aquarium sludge, organic waste, and break down organic compounds that cause dangerous conditions such as ammonia and nitrite poisoning, as well as low oxygen levels. By diligently consuming these pollutants, Stress Zyme™ keeps the aquarium gravel and filter clean, improves the development of your biological filter, and prevents the build-up of organic pollution that can inhibit nitrifying bacteria and promote disease-causing organisms. The bacteria are in a dormant spore state, becoming active upon addition to your aquarium.
Powerful Biological Cleaner: Contains over 300 million live bacteria per teaspoonful (5mL) to actively consume sludge, detritus, and organic debris.
Reduces Aquarium Maintenance: By consuming waste, it helps keep gravel, decorations, and aquarium glass cleaner, significantly reducing manual cleaning effort.
Improves Biological Filter: Assures an active biological filter by breaking down harmful organic pollutants that inhibit nitrifying bacteria.
Reduces Toxic Compounds: Helps to remove and manage dangerous ammonia and nitrite, contributing to safer water parameters.
Enhances Water Clarity: Promotes a cleaner aquarium, leading to visibly clearer water.
For Fresh & Saltwater: Safe and effective for use in both freshwater and marine aquarium systems.
No Refrigeration Necessary: The bacteria exist in a dormant spore form, ensuring a long shelf life (up to 5 years) without the need for refrigeration.
Safe for Aquatic Life: Completely harmless to fish, invertebrates, and aquatic plants.
For New Aquariums (Cycling): On days 1, 7, and 14, add 2 teaspoonfuls (10ml) for every 10 U.S. gallons (40 L) of aquarium water.
For Established Aquariums (Maintenance): Add 1 teaspoonful (5ml) per 10 U.S. gallons (40 L) of aquarium water weekly.
Shake well before using. Can be added while fish are in the tank.
Q: Can API Stress Zyme™ be added while fish are in the tank?
A: Yes, API Stress Zyme™ bacterial cleaner can be added while fish are in the tank.
Q: When should I use API Stress Zyme™ bacterial cleaner?
A: You may use it weekly, especially whenever you perform a water change (e.g., 25%) to help replenish beneficial bacteria and ensure your aquarium cycle functions normally.
Q: I just finished cycling my new tank but introduced many fish at the same time. Can I use Stress Zyme™ to increase beneficial bacteria for the increased bioload?
A: Yes, Stress Zyme™ will be very helpful in removing ammonia and nitrite (including nitrate) resulting from an increased bioload. If ammonia is not at zero, a combination of Stress Zyme™ and API AmGuard (for ammonia toxicity) can be very useful.
Q: Why does Stress Zyme™ not need refrigeration?
A: The bacteria in Stress Zyme™ are alive but exist in a dormant spore form, allowing them to withstand extreme temperatures and not require food or refrigeration until diluted in your aquarium water.
Q: Can Stress Zyme™ be overdosed?
A: It is very difficult to overdose Stress Zyme™. You can never truly have too much beneficial bacteria. The worst thing that could happen is a temporary bacterial bloom, which is rare and will clear on its own.
Q: I finished the suggested 7-day dosing, but my tank is still not fully cycled. Why?
A: Every tank cycles differently, so an exact timeframe is hard to give (generally 4-6 weeks). Stress Zyme™ significantly aids the process, and you can continue dosing if needed until the cycle is complete.
Q: If I plan to do a fishless cycle, do I need to add an ammonia source?
A: Yes, for expedited cycling times, add a pinch of fish food daily until you have an ammonia reading. Then, you can stop adding food and let the bacteria work.
API Stress Zyme™ is an essential product for all freshwater and marine aquarium owners, perfect for:
Setting up new aquariums to rapidly establish the biological filter.
Maintaining established tanks by consuming sludge and reducing organic waste.
Reducing ammonia and nitrite levels.
Simplifying aquarium maintenance and keeping tanks cleaner.
Promoting healthier fish and better water quality overall.
Need help with placing an order, delivery, or something else? Start with our Help Page — or message us anytime for support.