Seachem Stability Fish Tank Stabilizer - For Freshwater and Marine Aquariums, 16.9 Fl Oz (Pack of 1)
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Availability:
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Saturday, May 2
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Size: 500 ml / 16.9 fl oz
Color: Clear
Features
- TANK STABILIZATION: Seachem Stability will rapidly and safely establish the aquarium biofilter in freshwater and marine systems, thereby preventing the #1 cause of fish death: "new tank syndrome".
- TREATMENT: Stability is formulated specifically for the aquarium and contains a synergistic blend of aerobic, anaerobic, and facultative bacteria which facilitate the breakdown of waste organics, ammonia, nitrite, and nitrate.
- BACTERIA GROWTH: The necessary conditions for the growth of Stability's bacteria strains encompass a very broad range. When other bacteria begin to die off (usually from high organic loads caused by the unknown death of an organism), Stability simply becomes more effective.
- USE: Shake Seachem Stability well before use and turn off UV/ozone filter. Use 1 capful (5 mL) for each 40 L (10 US gallons) on the first day with a new aquarium. Then use 1 capful for each 80 L (20 US gallons) daily for 7 days. Fish and other aquatic species may be introduced at any time as long as dosage is maintained for 7 days.
Description
Seachem Stability Fish Tank Stabilizer - For Freshwater and Marine Aquariums, 16.9 Fl Oz (Pack of 1)
Brand: Seachem
Liquid Volume: 500 Milliliters
Item Weight: 1.09 Pounds
Item Form: Liquid
Manufacturer: Seachem Laboratories, Inc.
Is Discontinued By Manufacturer : No
Product Dimensions : 7.6 x 2 x 1.5 inches; 1.09 Pounds
Item model number : 123
Date First Available : June 20, 2004
Manufacturer : Seachem Laboratories, Inc.
Best Sellers Rank: #2,242 in Pet Supplies (See Top 100 in Pet Supplies) #8 in Aquarium Water Treatments
#8 in Aquarium Water Treatments:
Customer Reviews: 4.8 4.8 out of 5 stars (13,301)
Brand Name: Seachem
Manufacturer: Seachem Laboratories, Inc.
UPC: 781163660569 000116012300
Global Trade Identification Number: 00
Model Number: 123
Manufacturer Part Number: 123
Unit Count: 500 Milliliters
Item Type Name: Aquarium Water Treatments
Liquid Volume: 500 Milliliters
Item Weight: 1.09 Pounds
Item Form: Liquid
Pet Type: Fish
Target Species: Fish
Allergen Information: Gluten Free
Frequently asked questions
If you place your order now, the estimated arrival date for this product is:
Saturday, May 2
Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.
To initiate a return, please visit our Returns Center.
View our full returns policy here.
To initiate a return, please visit our Returns Center.
View our full returns policy here.
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Top Amazon Reviews
Size: 500 ml / 16.9 fl oz
Color: Clear
When I set up a small quarantine tank last year, I underestimated how quickly ammonia can spike in a fresh system. Within a day, I was staring at test kit colors I didn’t like. That’s when I reached for Seachem Stability, and it’s been part of my tank-start routine ever since. 🧪 Cycling Support Stability is designed to introduce beneficial bacteria that help break down ammonia and nitrite. In my experience, it noticeably smoothed out parameter swings during the first week of a new setup. It’s not instant magic, but it definitely supports the biological filter getting established faster than doing nothing. 🌊 Water Stability What I appreciate most is how it helps reduce that “new tank unpredictability.” When dosing as directed, ammonia and nitrite levels tended to stabilize more quickly, especially when I was cautious with feeding. It gave me a bit more confidence during those early days. 🐟 Livestock Safety I’ve used it with both freshwater fish and planted setups without seeing stress reactions. It’s marketed as safe for fish, plants, and invertebrates, and I haven’t noticed any cloudiness or negative side effects when using the recommended amounts. 🧴 Ease of Use Application is simple — shake well and dose according to tank volume. The instructions are clear, and you typically use it daily during the initial cycling period. It doesn’t have a strong smell, and it disperses easily in the water. ⏳ Expectations It’s important to keep realistic expectations: you still need to test water parameters and monitor ammonia, nitrite, and nitrate. Stability supports the process — it doesn’t replace proper cycling practices. Patience and regular testing still matter. 💰 Value for Money Considering how much livestock costs (and how stressful ammonia spikes can be), a bottle of Stability feels like inexpensive insurance for new setups or after major filter cleanings.
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Reviewed in the United States on February 23, 2026 by SAM
Size: 500 ml / 16.9 fl oz
Color: Clear
I used this in combination with Prime to do an in fish cycle and it worked great. It gives you instructions on the bottle - to use for 7 days or something like that - but I just kept going with it while I slowly added fish and it worked great. I started with a freshly planted tank and all the levels were zeroed out (Ammonia, Nitrite, Nitrate). I would dose Prime and Stability and a pinch of fish food daily in the morning and run water tests at night. The logic is, Prime would safely neutralize any Ammonia for 24 hours (while keeping it available for beneficial bacteria as a food source) and Stability would ensure there's enough beneficial bacteria to consume the available Ammonia and Nitrite. After a day or two, I added a few Guppies for their hardiness, hungry appetites, and large bioloads. In the meantime, I continued dosing Prime and Stability daily. 25% water change after a week with levels still good with some traces of Nitrate. A few Corydoras added to minimize leftover food from decomposing. Still dosing Prime and Stability daily. Fish thriving, plants thriving, and trace amounts of Nitrate. Kept dosing, but in somewhat smaller amounts, only using the recommended dose when adding fish. Months in, all is well with no deaths and a perfectly cycled tank. During the whole process I never saw any Ammonia or Nitrites spikes, even when adding fish. The Prime would keep Ammonia in check. And dosing Stability would make sure there's enough beneficial bacteria to handle whatever levels are in the tank, even if it fluctuates. Great product! Definitely recommend as I do most Seachem products.
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Reviewed in the United States on November 18, 2020 by Wes F.
Size: 500 ml / 16.9 fl oz
Color: Clear
I’ve been using Stability for years and very happy with it. The environment of the tank and water quality remains excellent between water changes and maintenance.
Reviewed in the United States on February 15, 2026 by Christopher Harrison
Size: 500 ml / 16.9 fl oz
Color: Clear
Must have for all newer and quarintine aquariums. Works as expected. Price is ok. Function is awesome. Easy to measure with the cap.
Reviewed in the United States on March 17, 2026 by William
Size: 500 ml / 16.9 fl oz
Color: Clear
Honestly the best for freshwater aquariums. Only need this and prime and your set!!
Reviewed in the United States on April 16, 2026 by M
Size: 500 ml / 16.9 fl oz
Color: Clear
This stabilizer has been simple to use and fits smoothly into regular aquarium maintenance. Dosing is clear, and it integrates well when setting up or maintaining a tank. It’s performed consistently with no issues and does exactly what it’s designed to do. The bottle size is practical and should last through multiple uses. Straightforward, reliable, and effective.
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Reviewed in the United States on January 11, 2026 by KaninAngMandaragat