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Availability:
In Stock.
Arrives
Sep 8 – Sep 9
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 ml
Item Weight: 1.1 pounds
Item Form: Liquid
Number of Packs: 1
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: #2,700 in Pet Supplies (See Top 100 in Pet Supplies) #11 in Aquarium Water Treatments
#11 in Aquarium Water Treatments:
Customer Reviews: 4.8 4.8 out of 5 stars (13,592)
Brand Name: Seachem
Number of Packs: 1
Unit Count: 16.9 Fluid Ounces
Manufacturer: Seachem Laboratories, Inc.
UPC: 781163660569 000116012300
Number of Items: 1
Global Trade Identification Number: 00
Item Type Name: Aquarium Water Treatments
Model Number: 123
Manufacturer Part Number: 123
Liquid Volume: 500 ml
Item Weight: 1.1 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:
Sep 8 – Sep 9
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
The Seachem stabilizer works great. I made the mistake of rearranging décor in my fish tank.Removing some and adding some new. Doing so , disturbed my beneficial bacteria causing some of my fish to die. Seachem Stability saved what fish I had left. I highly recommend this product. If You're setting up a new fish tank or doing some changes to your old tank.
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Reviewed in the United States on July 29, 2026 by Mae
Size: 500 ml / 16.9 fl oz
Color: Clear
I had some doubts about the product but actually boosted the time to get it cycled so fast, first week the amonia spike went from 4 to 0, the second week, nitrite went from 2 to 0, then finally got the nitrate in the thirs week, definitely recommend if you want to boost your progress, you can cycle with fish inside if the have low amount of waste like guppies but do costant small water changes and use conditioner with detoxifying like prime.
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Reviewed in the United States on August 1, 2026 by manuel
Size: 500 ml / 16.9 fl oz
Color: Clear
I use the product every time I clean my aquarium. Good results. Content bacteria that help my aquarium keeping its self control.
Reviewed in the United States on July 4, 2026 by Juan HR
Size: 500 ml / 16.9 fl oz
Color: Clear
Fabulous product that helps keep ph balance in my aquarium.
Reviewed in the United States on August 19, 2026 by Marcia M.
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'm sure Seachem Stability works well to stabilize and maintain a biofilter as it's advertised, but don't believe the hype that it will instantly cycle your biofilter. Sure, it can help get things off the ground by seeding the filter media with bacteria, but don't expect a colony of nitrifying bacteria in 24 hours or something ridiculous. When used with Seachem Prime you could probably reasonably perform a fish-in cycle in 7-10 days, but I'm in the camp that believes a fishless cycle with ammonium chloride and live plants is ideal. Having said that I found significantly better results using Fritz TurboStart 700 to kick off my nitrogen cycle. Stability didn't get me any results after a week using their recommended loading dose and maintenance dose. I'm somewhat certain it actually gave me a surface biofilm that I've never experienced before when using it to start a nitrogen cycle. Once the cycle has kicked off, I've diligently used Stability to 'maintain' my biofilter by adding it with water changes and stocking new animals. It's never given me problems, but it's honestly difficult to gauge how well it performs as there's no water test that can be done to see what kind of impact it makes to an already established tank. I suppose if you have a catastrophic crash in your biofilter or perhaps overload it you could measure its before-and-after performance with ammonia and nitrite tests, but thankfully I haven't experienced anything like that. I'll continue to use Stability, Prime, and Pristine in maintenance doses as suggested because as far as I know, it's working as intended, and making changes to a stable environment is a recipe for disaster. I just haven't had luck with it kick-starting the nitrogen cycle. For that I'd put my faith in Fritz TurboStart (or FritzZyme)
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Reviewed in the United States on August 14, 2021 by Christopher Lang
Size: 500 ml / 16.9 fl oz
Color: Clear
I’ve been using Seachem Stability regularly during water changes for my freshwater aquarium, and it has been one of those products I continue to repurchase because it simply works. I add it during maintenance and water changes to help support the biological balance in the tank, and I’ve never had any issues while using it. Fish behavior stays normal, water parameters remain stable, and I’ve had good overall tank health using this as part of my routine. What I like most is the peace of mind it provides, especially after larger water changes or filter maintenance where you want to help protect the beneficial bacteria system. The liquid is easy to dose, and a bottle lasts quite a while depending on tank size and maintenance schedule. Overall, this has been a very reliable aquarium product in my experience. I’ve used it consistently for freshwater tanks with no problems, and it continues to work well as part of regular tank maintenance.
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Reviewed in the United States on May 19, 2026 by JustAShopper
Size: 500 ml / 16.9 fl oz
Color: Clear
Stability helped me start and establish a brand new 55G tall from scratch with only one fish departing to the Golden Pond in the Sky (loach swam up the intake into the filter impeller...messy). From day one I did daily testing with the API kit and made an Excel spreadsheet of the data. There were very small, irregular ammonia spikes at the 2nd/3rd week, but not into the "danger" zone and slowly decreased to 0ppm by the end of the 4th week. Nitrites and nitrates increased from the 3rd week and then hovered at a "very acceptable" range below danger zone and then gradually decreased to ~0 ppm for nitrites and ~20ppm for nitrates by the 5th/6th week. The results I got from the test kit were evaluated against a U of Florida's chart (I am a bio major) of Total Ammonia Nitrogen Toxicity (using pH and water temperature as the other parameters), and were in the range that is deemed not dangerous to FW fish for a short term period. With the results of these API test and my personal experience, I would definitely recommend and have been using Seachem Stability as a "jump start" product to establish the important biological filter in a FW aquarium or to boost or supplement the already existing bio filter in an established tank. For those interested about my experience, see below for in depth details. Products used: -Seachem Stability -Seachem Prime -API FW Master Test Kit 1st week: IMPORTANT: FOLLOW THE DIRECTIONS FOR THE FIRST WEEK'S DOSING SCHEDULE BASED ON YOUR TANK'S VOLUME. Added 7 Zebra danios. These are hardy fish and can survive a newbie's foray into fishkeeping and hopefully any mistakes I make. First day: One capful( 5mL) for every 10G of NEW WATER, so 5 capfuls. Days 2-7: One capful for every 20G of water, so ~3 capfuls EVERYDAY. Added 4 black Java loaches/khuli loaches on day 3. Note: Directions says you can add fish/inverts immediately and at any time as long as you follow the all-important dosing schedule above for the FIRST week only. NOTE: After first week, one capful for every 20G once a month, or with each water change, or introducing new fish, or medicating. 2nd week: Added Dwarf gourami and 3 Albino cories. Did 25% water change with Prime, then dosed with 3 capful of Stability, which is the dose for ~60G. 3rd week: Added Bristlenose pleco. Did 25% WC with Prime, then dosed with 3 capful of Stability. 4th week: Added 3 more Albino cories. Added 1teaspoon/10G API Aquarium salt to counter increasing ammonia, nitrites and nitrate spikes. 5th week: Added 5 more loaches. Did 25% WC with Prime, then dosed with 3 capful of Stability. 6th week: Added 2 Amano shrimps. Did 25% WC with Prime, then dosed with 3 capful of Stability. 4 months later: 3 Bamboo shrimps, 2 Amano shrimps, 9 Loaches, 6 Cories, Dwarf gourami, 7 Danios, BN pleco, plants. All fish/inverts growing and healthy. I now only dose 1 capful of Stability with each 25% WC, as my biofilter is now well established and API tests show it doesn't need 3 capfuls for every WC. Thanks Stability!
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Reviewed in the United States on September 19, 2013 by Johnny