Stability — Fast-Cycling Nitrifying Bacteria for Marine and Freshwater 250 ml and 500 ml - Seachem

Seachem Stability is the leading solution for quickly establishing a functional biological cycle in a new marine or freshwater aquarium. Its patented formula contains a synergistic blend of aerobic, anaerobic, and facultative bacteria in spore form — immediately active upon introduction into the aquarium — that facilitate the breakdown of organic waste, ammonia, nitrites, and nitrates. Stability prevents new tank syndrome, the leading cause of fish mortality in captivity. Available in 250 ml and 500 ml.

Why Stability's Spore Bacteria Are Superior

Most cycling products on the market contain active bacteria that require refrigeration to survive and whose viability declines rapidly after opening. Seachem Stability uses a radically different and more effective approach: its bacteria exist in a spore state — alive but metabolically dormant. In this state, they withstand extreme temperatures, require no food to survive, and maintain an exceptional shelf life of 6 years without refrigeration.

Upon introduction into the aquarium, dilution in water instantly activates the spores, which begin to colonize available surfaces — filter, substrate, live rock — within the first 24 hours. No rehydration delay, no loss of effectiveness from transport or room-temperature storage.

The Nitrogen Cycle — Why Stability Is Essential

In any aquarium, the organic waste produced by fish, corals, and uneaten food generates ammonia — a highly toxic compound even at very low concentrations. Without an established bacterial population, this ammonia quickly accumulates to levels lethal to your livestock.

The natural nitrogen cycle transforms ammonia into nitrites via Nitrosomonas and Nitrosospira bacteria, then nitrites into nitrates via Nitrospira — much less harmful and easily controlled with water changes. Without intervention, this process naturally takes 4 to 8 weeks. Stability dramatically shortens that timeframe by directly inoculating your filter with massive concentrations of these beneficial bacteria.

Unlike competing products whose bacteria require very specific temperature, pH, and organic-load conditions to survive, Stability's bacterial strains work across a very wide range of conditions. Where other bacteria collapse under a high organic load, Stability becomes even more effective.

When to Use Seachem Stability

Cycling a new aquarium

This is Stability's primary use. From day one, dose generously and keep dosing for 7 consecutive days. Fish and other aquatic specimens can be introduced at any time during the dosing period — Stability is completely harmless to all aquatic life, and it is virtually impossible to overdose. When cycling without fish, add a pinch of food daily to give the developing bacteria an ammonia source.

Adding new livestock

Each significant introduction of new fish or corals suddenly increases the biomass and organic load of your system. A dose of Stability with each addition prepares your biological filter to absorb the increase without an ammonia or nitrite spike that would stress existing and new specimens alike.

After medication

Antibiotics and antiparasitics used in quarantine or emergency treatment destroy beneficial nitrifying bacteria along with pathogens. Turn off UV and ozone during treatment, then dose Stability for 7 consecutive days to quickly rebuild your biological filter and avoid a dangerous post-treatment mini-cycle.

Regular biofilter maintenance

A monthly dose of Stability keeps your filter's bacterial populations at peak efficiency, strengthening your system's resilience to accidental organic overloads — unexpected mortality, overfeeding, temporary filtration failure.

Biological emergency

Biological crash after a prolonged power outage, accidental overheating, or mass die-off — Stability is the first tool to reach for in a crisis. Combine with Seachem Prime to chemically detoxify ammonia while the bacteria recover biologically.

Official Seachem Protocol

• Shake well before use
• Turn off UV and ozone — for the full 7-day cycle, or at least 24 hours for maintenance additions
• Day 1 — new aquarium: 5 mL (1 capful) per 40 L (10 US gallons)
• Days 2 to 7: 5 mL per 80 L (20 US gallons), daily
• Maintenance: 5 mL per 80 L, once a month, with each water change, when adding livestock, or during medication
• Shelf life: 6 years — no refrigeration required

Choosing your size

• 250 ml — 50 maintenance doses of 5 ml: perfect to start a standard-size tank.
• 500 ml — 100 doses of 5 ml: a full cycle on a large system plus months of maintenance, without running out at the wrong time.

Why buy at ReefSolution

Marine aquarium specialists in Laval: in-store advice and shipping across Canada. For a solid tank start:

• Seachem Pristine — bio-augmentation that tackles detritus and biofilm once the cycle is established.
• CaribSea Arag-Alive Special Grade — live sand that starts the tank with its own bacteria.

Frequently asked questions

Can you overdose Seachem Stability?

It is virtually impossible, according to Seachem — you can never have too much beneficial bacteria. At worst, a passing bacterial bloom in the water column, which is rare and clears on its own.

Does Stability need to be refrigerated?

No. The bacteria are in spore form: 6-year shelf life from the date of manufacture, no refrigeration.

Can fish go in during cycling with Stability?

Yes — Seachem states fish can be introduced at any time during the 7-day dosing period. Stability is harmless to all aquatic life.