Last Updated on February 10, 2023 by Matt

In this review article we will give a detailed account of Seachem Stability. 

Seachem Stability is an aquarium bacteria supplement which is designed to prevent new tank syndrome. It contains bacteria which will colonize the biological filter, mechanical filtration media pads, and the substrate.

We will put it through its paces, and note the top features, sizing’s, ease of use, it’s downfalls and answer some frequently asked questions. 

Seachem Stability -1L
  • New tank stabilization system for marine and freshwater
  • Rapidly and safely establishes bio-filter
  • Prevents "New Tank Syndrome"


Top Features of Seachem Stability

Top Features of Seachem Stability

Seachem Stability has some amazing features that makes it arguably the best aquarium bacteria supplement on the market. At least looking at the reviews and the reputation that it has you’d say that it is definitely up there. But what has caused it to have such a good reputation? 

By far the best feature that Seachem Stability has is the choice of bacteria that it uses to get the job done. 

With a synergistic mix of aerobic, anaerobic, and facultative bacteria you are benefited with both nitrification and denitrification processes. If you remember from the aquarium nitrogen cycle, these processes are fundamental in removing dangerous nitrogenous compounds from the water column that are the result of organic matter decomposing. 

Nitrifying bacteria are aerobic, they need oxygen, and convert ammonia to nitrite, and nitrite to nitrate. Denitrifying bacteria convert nitrate to atmospheric nitrogen. 

Ammonia is incredibly toxic, and even in small concentrations will cause ammonia poisoning. Nitrite is also very toxic, but nitrate is much less so. However at high concentrations nitrate will still cause nitrate poisoning in your fish. 

Most aquarium bacteria supplements only contain nitrifying bacteria, and so don’t provide bacteria for nitrate removal. The fact that Seachem Stability does is great. 

Another great feature is that as the bacteria aren’t active in the bottle, they are in spore form, they will last a very long time. The shelf life of Seachem Stability is 4 years, and you don’t have to refrigerate it. As you add the bacteria to your fish tank they will activate and become live. 

The bacteria used are non sulfur fixing and so will not produce hydrogen sulfide. It is completely safe for all aquatic organisms, plants and fish alike, and there is not a danger of overuse. 

The downfall of many bacteria supplements is that the bacteria they use have a limited range of conditions that are needed for growth, inhibiting the effectiveness of the product if your tank falls outside of these requirements. This isn’t the case with Seachem Stability. The bacteria have a wide range of environmental conditions that they can thrive in ensuring that your tank will feel the full effects, whilst also making this product suitable for all freshwater, saltwater, and reef tanks. 

Bottle Sizing

There are seven different bottle sizes available for Seachem Stability. These are 50 mL, 100 mL, 250 mL, 500 mL, 1 L, 2 L, and 4 L. 

This is a very wide range of bottle sizings, so you can choose the size most appropriate for your tank, and the amount that you will need to use. 

With a 4 year shelf life, it might be a good idea to choose a bigger size than you necessarily need, so that you can minimize the overall cost and plastic use. 

Ease of Use

Seachem Stability is extremely easy and simple to use. You should use it when you are first cycling and setting up a new tank, and after water changes and tank and filter cleanings

For new tanks, to cycle the tank quickly you should use 1 capful (5 mL) per 10 gallons on the first day, then for 7 subsequent days 1 capful per 20 gallons. Fish and other species can be added at any time as long as you maintain this dose. 

After aquarium filter cleanings, water changes, or adding new fish to mature tanks you should use 1 capful per 20 gallons to maintain the biological filter. This will enable the colonies of beneficial bacteria to continue to provide nitrification and denitrification process. 

If you are running an aquarium UV sterilizer you will need to turn it off for the 7 day dose cycle if you are cycling a new tank, or for 24 hours after dosing after a water change or cleaning. The bacteria take 24 hours to activate and find a home, so you need to wait that long before turning back on the UV sterilizer, otherwise you will kill the bacteria.


As previously stated in this Seachem Stability review, this aquarium bacteria supplement can be used in all freshwater, saltwater, and reef tanks. 

You don’t have to purchase a different product for each tank as with other brands, you simply need a bottle of this on hand and you will be able to use it in all and any aquariums that you may have. 


There aren’t many negatives to speak of when talking about Seachem Stability. 

However you will have to make sure that you have the correct biological filtration media to house the bacteria. Denitrifying bacteria are anaerobic, that is they need the absence of oxygen. To provide this you need a very porous and dense media. 

A perfect media for this is Seachem Matrix, which has been developed and designed with exactly this in mind. If you use this media with Seachem Stability then you will be able to see the full effects in your tank.

Seachem Stability FAQs

In this section we will answer some of the most frequently asked questions about Seachem Stability. If you have any other questions, or would like further information on the questions answered, please leave a comment!

How often should you use Seachem Stability?

You should use this product when you are first setting up and cycling a new tank, after water changes, after filter cleanings, and after adding new fish. You can’t overuse this product; if you use too much then the excess bacteria will simply die off and be eaten by fish or invertebrates or be removed by the filter. Water changes can be made easier using the Python water changer.

How much Seachem Stability should you use?

When cycling a new tank you should use 1 capful (5ml) per 10 gallons on the first day, then 1 capful per 20 gallons daily for 7 days. 

After water changes, tank cleanings, or adding new fish you should use 1 capful per 20 gallons.

How does Seachem Stability compare to other brands?

So how does Seachem Stability compare to some of its closest competitors?

Seachem Stability vs API Quick Start: API Quick Start is a brilliant aquarium bacteria supplement, but only contains nitrifying bacteria so will only remove ammonia and nitrite. It doesn’t contain denitrifying bacteria to remove nitrate like Seachem Stability. It is also designed for freshwater tanks, with a separate product for saltwater tanks, though it could be used on saltwater too. 

Seachem Stability vs Tetra Safestart: Tetra Safestart only contains live nitrifying bacteria, it doesn’t contain denitrifying bacteria like Seachem Stability. Therefore it will remove ammonia and nitrite but won’t remove nitrate. Tetra Safestart can only be used on freshwater tank setups.

Seachem Stability vs DrTim’s Aquatics One & Only: DrTim’s Aquatics One & Only offers three different products for freshwater, saltwater, and reef tank setups. Seachem Stability is able to be used on all of these tank setups, therefore being much more flexible. DrTim’s Aquatics also needs to be refrigerated, while Seachem Stability doesn’t.

Conclusion – Seachem Stability Review

Hopefully this Seachem Stability review has been useful! If you want a brief overview on this product here you go:

Seachem Stability is a brilliant aquarium bacteria supplement which contains bacteria which will remove ammonia, nitrite, and nitrate from the water column. It is arguably the best on the market!

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