- Sku: 124
- Vendor: Seachem
Seachem Stability
Seachem Stability rapidly and safely establishes the biological filter in both freshwater and saltwater aquariums, heading off the number one cause of fish loss: new tank syndrome. Dose it when you set up a tank, add livestock, change water, or clean your filter, and the beneficial bacteria go to work breaking down ammonia and nitrite before they can harm your fish. It is a core part of our water care and maintenance lineup.
How Stability Works
Stability contains a synergistic blend of aerobic, anaerobic, and facultative bacteria that break down waste organics, ammonia, nitrite, and nitrate. The strains are non-sulfur fixing, so unlike some competitors they will never produce toxic hydrogen sulfide. It is completely harmless to fish, invertebrates, and plants, and it cannot be overdosed, which makes it foolproof for new hobbyists.
Why Aquarists Trust It
- Prevents new tank syndrome by seeding the biofilter fast, so a fresh setup can be stocked sooner.
- Works in fresh and saltwater, one bottle for community tanks, planted setups, and reef systems.
- Will not produce hydrogen sulfide, the non-sulfur bacteria stay safe even when dosed heavily.
- Safe for every inhabitant, harmless to fish, shrimp, snails, and live plants, with no risk of overuse.
- Rescues struggling tanks, redose after medicating, deep cleaning, or restocking to rebuild the colony.
How to Use
New aquarium: add 1 capful (5 mL) per 10 US gallons (40 L) on the first day, then 1 capful per 20 US gallons (80 L) once daily for the next 7 days. Established tanks: add 1 capful per 20 US gallons once a month, or with each water change, filter cleaning, or new addition. Shake well before use. Stability works alongside any dechlorinator and will not clash with medications.
Choose Your Size
| Size | Maintenance Doses Treat Up To | Best For |
|---|---|---|
| 50 mL | ~200 gal of dosing | Nano tanks and quick top-ups |
| 100 mL | ~400 gal of dosing | A single small or medium tank startup |
| 250 mL | ~1,000 gal of dosing | Multiple tanks or larger setups |
| 325 mL | ~1,300 gal of dosing | Value size for regular dosers |
| 500 mL | ~2,000 gal of dosing | Fishrooms, shops, and big systems |
Specifications
| Brand | Seachem |
| Type | Biological filter supplement (live bacteria) |
| Water Type | Freshwater and saltwater |
| Targets | Ammonia, nitrite, nitrate, waste organics |
| Startup Dose | 5 mL per 10 gal day one, then per 20 gal for 7 days |
| Safe For | All fish, invertebrates, and plants |
| Available Sizes | 50 mL, 100 mL, 250 mL, 325 mL, 500 mL |
Recommended Pairings
- Seachem Prime removes chlorine and chloramine so your new water is safe for the bacteria to colonize.
- Seachem SureStart Pack bundles Prime, Stability, and Pristine for a complete new-tank starter kit.
- Seachem ParaGuard handles parasites and fungus, redose Stability afterward to rebuild the colony.
- Browse our live fish once your tank has cycled and is ready to stock.
Frequently Asked Questions
Can I add fish right after dosing Stability?
Stability lets you stock a new tank much sooner than an unaided cycle. Add fish gradually over the 7-day startup, testing your water to be sure ammonia and nitrite stay in check.
Does it need to be refrigerated?
No. Stability is shelf stable and does not require refrigeration, though a cool, dark cupboard keeps it at its best.
Will medications kill the bacteria?
Some treatments can set back your biofilter. After a course of medication, redose Stability to rebuild the colony.
Can I overdose it?
No. Stability is harmless to all aquatic life, so extra doses during stressful periods will not hurt your fish or plants.
Have a question?
Seachem Stability
