API Stress Coat Aquarium Water Conditioner

Rated 4.7737 out of 5 stars


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About This Item


  • Fast-acting formula conditions tap water for use in freshwater aquariums.
  • Helps reduce chlorine, chloramines and heavy metals that can harm your finned friend.
  • Aloe vera extract helps repair and protect your fish’s slime coat from damage caused by fighting, handling or shipping.
  • Use when adding or changing water, adding a new fish, or when your fish is sick or injured.
  • Each 5-gallon container treats over 7,600 gallons of aquarium water.

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Play Video: Learn More About API From Our Team of Experts
Learn More About API From Our Team of Experts

Special Note
  • 1-oz bottle treats up to 60 gallons.
  • 8-oz bottle treats up to 470 gallons.
  • 16-oz bottle treats up to 940 gallons.
  • 64-oz bottle treats up to 3786 gallons.
  • 1-gal treats up to 7600 gallons.

About API Water Conditioners

It’s Smart To Be Proactive!

The best way to keep your aquarium clean is to maintain good water quality. This will help keep your fish strong and vibrant and prevent disease. Water conditioners and test kits from API can help you keep your aquarium water safe and healthy.

How Do I Maintain a Healthy Environment?

It is important to test your aquarium water weekly to ensure it stays healthy for your fish.  In addition, a bi-weekly partial water change of no more than 25% will help reduce toxic buildup, remove debris the filter missed, and replenish the oxygen available to your fish.

Feed Twice Daily and Test Water Weekly

Feed your fish twice a day, check their water temperature, and observe them to make sure they are active. You should also test water quality weekly for optimal safety. For fish to thrive, their water must closely match that of their natural environment—poor water quality can cause stress, illness and even fish loss. The 6 important parameters for healthy aquarium water are ammonia, nitrite, nitrate, pH and water hardness (GH & KH). All of these can vary over time and are invisible to the eye.

Change Water and Restore the Ecosystem

In a closed aquarium environment, there are no natural rivers or streams to carry away debris and other waste materials. That is why you should replace 25% of your aquarium water every two weeks, making sure to add water conditioner to your tap water to make it safe for your fish. You should also change your filter media and clean your gravel monthly. Adding beneficial nitrifying bacteria with API Quick Start when you do will help restore your aquarium’s fragile ecosystem and avoid disruption.

What Do API Products Do and When Do I Use Them?

API Test Kits

Use test kits weekly to monitor water quality parameters, which can vary over time and impact the health of your fish.

API Stress Zyme

Using this every week will help keep your aquarium clean and your gravel and ornaments sludge-free.

API Algaefix

Use weekly to control algae growth and keep aquarium glass, ornaments and plants clean.

API Stress Coat

Use every 2 weeks during water changes to make tap water safe, and when adding fish, or when fish are injured.

About API

The team at API has a passion for fish and understands the rewards and relaxation fishkeeping can bring. For almost 60 years, they have developed premium products with a focus on proven and effective results. API offers a range of testing kits, water conditioners and nutritionally superior fish foods. They are dedicated to making a better underwater world for the benefit of fish and those who keep them.

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Fish TypeBetta, Bottom Feeder, Cichlid...BettaMarine Fish, Tropical FreshwaterBettaTropical Freshwater
Aquarium TypeSaltwater, FreshwaterFreshwaterSaltwater, FreshwaterFreshwaterFreshwater

Questions & Answers

38 Customer Questions

Is this ok for African dwarf frogs too? I have been using it in my community tank with the frogs in it along with the fish
Answer by ChewyAug 23, 2018
This product is not formulated for amphibians.

When using this product do i still have to use a regular water conditioner or do i use just this ans nothing else?
Answer by ChewyDec 22, 2018
This product removes chlorine and chloramines so no other conditioner is needed. Additionally, it detoxifies heavy metals, reduces fish stress and replaces the slime coat on your fish.

I am barely going to buy this after using a plain water conditioner. Would I have to do a complete water change with API stress coat in order to get the best results for the benefits it offers?
Answer by ChewyFeb 06, 2018
A complete water change would not be necessary if using this product as directed.

Do I use this every day like a typical betta water conditioner, or just after doing water changes?
Answer by ChewyFeb 19, 2018
The conditioner should be used when setting up an aquarium, adding or changing water, when adding a new fish, or when fish are damaged by injury or disease.

ReviewsWrite a Review

Rated 4.7737 out of 5 stars
137 Ratings
Would recommend to a friend

137 Customer Reviews

Rated 1 out of 5 stars
By sehickam on Sep 7, 2023

Dead fish

My 5 year old goldfish had a few black areas and I read reviews about this product and gave it a try. My fish died 2 days later. If I could I would give this zero stars

Rated 5 out of 5 stars
By camilo2 on Jul 28, 2023

Ik have had aquarium for years and this has been a great product . I always buy Gallon for my 100 gallon aquarium.

Rated 5 out of 5 stars
By chase on May 21, 2023

stress coat

I have been adding it to my water changes, don't really see any changes in the conditions. I guess its okay, my fish are still okay.

Rated 5 out of 5 stars
By thebklynblujay on Feb 12, 2023

a must have product!

I have been an aquarium hobbyist for over 10 years, and this product is an absolute must have! Regular water changes are an important practice for overall health of your fish and aquarium. This product dechlorinates your tap water effectively and helps your fish maintain a healthy slime coat in the process. Safe for your planted aquarium as well, which is also a plus. Happy fishkeeping!

Rated 5 out of 5 stars
By June on Apr 25, 2023

Stress coat

API stress Coat works great for soothing red spots on Koi caused by stress or environmental elements.

Rated 5 out of 5 stars
By Betty on Jan 23, 2023

PERFECT Smaller Size Stress Coat

Very pleased with this product and have used it for years. Love the tiny size you I can use for smaller amounts of the needed quanities to replace water in my aquarium. Will always be back to get this and you should too.

Rated 5 out of 5 stars
By Kkkk on Dec 20, 2022

Stress coat

Stuff works quick to stabilize water and remove any chlorine or nitrites. Been using for over 5 years

Rated 5 out of 5 stars
By Yuricat on Nov 3, 2022
Top 500 Contributor

Aquarium Water Conditioner

this works very well for my 29 gal tank, my big Black Moore fish are doing just great and was a good price.

Rated 5 out of 5 stars
By Judy on Jul 3, 2022

very reliable water conditioner

I have used this product for 10 years in my water feature. I put approximately 1/3 of a cup once a week in what I would guess is around 100 gallons of tap water. I have never lost a fish in all that time except for the one time my cat decided his new hobby was fishing. He was only able to catch 2 out of 15 and one lived through the ordeal. I believe the water conditioner helped to save her.

Rated 5 out of 5 stars
By Squirrel1 on Nov 17, 2022

Works well

Does what it says nice stuff highly recommend will buy again