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API

API STRESS ZYME Freshwater and Saltwater Aquarium Cleaning Solution 16-Ounce Bottle

  • Based on 12,182 reviews
Condition: New
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Availability: In Stock.
Fulfilled by Amazon
Arrives Monday, Oct 12
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Size: 16 oz


Features

  • Contains one (1) API STRESS ZYME Freshwater and Saltwater Aquarium Cleaning Solution 16-Ounce Bottle
  • Keeps freshwater and saltwater aquariums clean and reduces maintenance
  • Consumes sludge to help keep gravel and decorations clean
  • Adds beneficial bacteria for a healthy aquarium
  • Use weekly to maintain a clean, healthy aquarium

Description

Reduce aquarium maintenance by creating a naturally balanced aquarium with API STRESS ZYME Freshwater and Saltwater Aquarium Cleaning Solution. Fish waste, sludge, uneaten food and other organic compounds can cause harmful water conditions including ammonia and nitrite poisoning and breathing difficulty. They can also be difficult and time-consuming to remove especially from rock, coral and gravel. API STRESS ZYME Freshwater and Saltwater Aquarium Cleaning Solution contains over 300 million live bacteria per teaspoonful to consume sludge and organic debris, keeping gravel and glass clean naturally and boosting the natural aquarium cycle, reducing aquarium maintenance over time. Use it weekly in freshwater and saltwater aquariums to maintain a strong biological filter and a healthy, clean aquarium. With API aquarium products, it’s easy to keep a beautiful saltwater, freshwater or reef aquarium. For almost 60 years API has developed premium solutions with proven and effective results for your family and ours. API offers a range of testing kits, water conditioners, and nutritionally superior food, because we’re dedicated to making a better underwater world. They work to provide a safe, hospitable environment for fish such as tropical community fish, cichlids, goldfish and more. At API, we understand the rewards and relaxation of fishkeeping because we have a passion for fish too.

Brand: API


Liquid Volume: 473 ml


Item Weight: 544.31 g


Item Form: Liquid


Number of Packs: 1


Product Dimensions ‏ : ‎ 10 x 10 x 10 inches; 1.2 pounds


Item model number ‏ : ‎ 56E


Department ‏ : ‎ Unisex-Adult


Date First Available ‏ : ‎ June 20, 2004


Manufacturer ‏ : ‎ Mars Fishcare


Best Sellers Rank: #4,169 in Pet Supplies (See Top 100 in Pet Supplies) #18 in Aquarium Water Treatments


#18 in Aquarium Water Treatments:


Customer Reviews: 4.8 4.8 out of 5 stars (12,182)


Brand Name: API


Number of Packs: 1


Unit Count: 1 Count


Manufacturer: Mars Fishcare


UPC: 317163160565


Number of Items: 1


Global Trade Identification Number: 65


Item Type Name: Aquarium Sludge Remover


Model Number: 56E


Manufacturer Part Number: 56E


Liquid Volume: 473 ml


Item Weight: 544.31 g


Item Form: Liquid


Pet Type: Fish


Target Species: Fish


Allergen Information: Apple Free


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Monday, Oct 12

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.

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Similar Products

Top Amazon Reviews

    • I can see clearly now!
Size: 8 oz
Review Image by daniel spivey
Review Image by daniel spivey
Review Image by daniel spivey
This product is highly effective! If you're seeking a solution to clarify your tank water and diminish the amount of sludge, which in turn reduces any unpleasant fishy odors, this is an essential purchase. I've been utilizing this product for several months to aid in the general maintenance of my fish tanks. Its application is straightforward; simply follow the instructions provided, and you'll find it impossible to make a mistake. ... show more
Reviewed in the United States on May 25, 2026 by daniel spivey
    • Keeps filter clean and biofiter optimum
Size: 16 oz
I add this once a week. The first three months of using it I went to clean my canister filter and was surprised to see virtually no gunk! Normally there was a lot of build up. This made a huge difference. My tank is crystal clear because of this and it's enhancement of the bio filter. This stuff eats all the sludge on your biofilter and makes it work better. This is NOT nitrifying bacteria like quick start. This product will not cycle your tank. This just keeps maintence low and healthier fish. I now wait 5 to 6 months to clean my two fluval 406s. I have a 40g African cichlids tank that is heavily over stocked and they are dirty fish! Thank you API! Update 10/18/2019 I just wanted to reiterate how happy I am with this additive. I also notice that my nitrates are consistently almost zero and I hardly get anything out of vacuuming the gravel. (Only fresh large poop) I used to pick up a cloud of dirt everywhere with my siphon. I do run carbon to help sparkle the water because I have driftwood that tries to turn it yellow but the clarity is crystal with this stuff. And always my Fluval 407 (now) hardly has any build up and the biohome ultimate is perfectly clean. I briefly tried seachem’s pristine but this seems to be the best. Fish are very happy. ... show more
Reviewed in the United States on October 15, 2017 by Amazon buyer
    • If you have fish you need this
Size: 16 oz
Works great to keep a tank clean and fish healthy. Use it every water change and weekly. Wouldn’t do without it. Definitely cleaning the tank less now
Reviewed in the United States on July 28, 2026 by heidi
    • Effective, fast and safe
Size: 16 oz
This stuff works so good. If you have algae/sludge issues, get this stuff, safe, fast and effective. I have a 15 gallon tank that underwent an algae bloom after some of my long-term release plant food tablets broke into the tank water. I’ve been battling a nasty case of hair algae ever since. I just put this stuff in yesterday and can all ready tell a big difference with my plants not being as covered. ... show more
Reviewed in the United States on July 4, 2026 by Fr. R. O.
    • ... used Stress Zyme for quite awhile and had relatively good experiences with it
Size: 16 oz
I've used Stress Zyme for quite awhile and had relatively good experiences with it. More recently though I've moved to Seachem Stability and found that I prefer it. The Seachem product is more expensive but I've had great success with their line of products and find that Stability works great. Having said that I don't' want to give a negative impression of API's Stress Zyme. It does a good job of establishing and maintaining your biological filtration which is solely responsible for keeping your tanks nitrogen cycle in check. The Stress Zyme, like other "bottled bacteria", is a blend of anaerobic and aerobic bacteria and a "slime coating" agent that helps keep fish happy and healthy. The bacterial agents don't seem to be as "potent" as some others I've used like I mentioned earlier. But, the slime coat portion is more noticeable. When Stress Zyme goes into the water you can see that it has an almost oily consistency that rapidly dissipates into the water column and I'm sure does a good job of keeping your fish... hmm... lubricated (for lack of a better word). Water parameter tests have come up good with API Stress Zyme and there seems to be no negative effects on any of my fish or plants from using or even overdosing it. It's relatively inexpensive and does a good job. If you can't afford Seachem Stability (which I think is a better product) I wouldn't hesitate to recommend Stress Zyme. ... show more
Reviewed in the United States on March 29, 2015 by Christopher Lang
    • Great product
Size: 16 oz
Works great! Simple directions and great value for the price.
Reviewed in the United States on February 27, 2026 by Kindle Customer
    • Been using it since day 1!! Read why!!
Size: 16 oz
Review Image by Mike S.
Review Image by Mike S.
Review Image by Mike S.
Review Image by Mike S.
Review Image by Mike S.
Review Image by Mike S.
Review Image by Mike S.
Review Image by Mike S.
Review Image by Mike S.
API STRESS ZYME has been my product of choice since the 1st day I established my 55 gallon aquarium back in 2018, photos included. It's so easy to use, just read the instructions. Dependent on how many gallons is how much product you need to use. The live bacterias do wonders for the fish, as I've been using it with every water change which is every 3 to 4 weeks. You can also use it weekly to maintain the biological filter in your aquarium, however I did not find any need for that, since the 55 gallon tank, with 30 fish creates its own biological filter. You always want to shake it well and for every 10 gallons of water change, you will add 5 ml off API stress zyme. The dosage is marked on the cap, making it really easy to use. Overall I am using quite a few products from API to maintain the tank filter and the life for my fish. I highly recommend this product, as I've been a frequent user for the last 6 years!! ... show more
Reviewed in the United States on March 3, 2024 by Mike S.
    • Excelente
Size: 1 gal
100% recomendada excelente
Reviewed in the United States on July 3, 2026 by Wilfredo Greo

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