API Stress Coat with Pump Aquarium Water Conditioner, 16-oz bottle

Rated 5 out of 5 stars
$19.09Chewy Price
$18.14Autoship Price
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About This Item


  • Works to make tap water safe by helping to remove chlorine, chloramines, and detoxify heavy metals.
  • May help reduce fish stress by up to 40% by helping to remove harmful chemicals and make tap water safe.
  • Contains soothing aloe vera, which is scientifically tested to help reduce fish stress, heal damaged tissue and promote regeneration of tissue.
  • Forms a synthetic slime coating that replaces the natural secretion of slime to help reduce susceptibility to disease.
  • Use when starting a new aquarium, adding or changing water and adding fish.

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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

16-oz bottle treats up to 940 gallons.

Frequently Bought Together

Omega One Betta Buffet Flakes Fish Food, .28-oz jar
Rated 4.5263 out of 5 stars
$3.80Chewy Price

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Total Price: $31.63

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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Questions & Answers

3 Customer Questions

Answer by ChewyJan 17, 2022
This water conditioner can be used with turtles.

dose this help keep the water clear too?
Answer by ChewySep 27, 2019
Stress Coat removes chlorine and neutralizes chloramine and heavy metals. It also reduces stress in fish and promotes the healing of wounds and regeneration of damaged tissue.

Not sure if I need this or not but would well water put stress on Koi fish in the aquarium?
Answer by ChewyFeb 04, 2019
API MARINE STRESS COAT is solely for use in marine (saltwater) aquariums. We also carry the API STRESS COAT for regular freshwater tanks. Typically, it is not recommended to use well water in a fish tank.

ReviewsWrite a Review

Rated 5 out of 5 stars
6 Ratings
Would recommend to a friend

6 Customer Reviews

Rated 5 out of 5 stars
By MunchieMom on Aug 8, 2021

Great stuff

This definitely helps keep my fish calm when I do water changes.

Rated 5 out of 5 stars
By Fishy on Dec 10, 2020

Good product and terrific customer service

This product works exactly as advertised for our fish, both as a water conditioner and to help damaged fish. Equally important, Chewy's customer service was great. I was initially shipped the wrong item by mistake. I used the chat feature to speak with a customer service representative who immediately shipped out the correct item and asked me to donate the incorrect item. Nobody's perfect and Chewy's handled their mistake very well.

Rated 5 out of 5 stars
By Bruno on May 31, 2019

API products are great.

Love the pump option. Over possible spilling with a cap. Thanks for offering this.

Rated 5 out of 5 stars
By Mean on Mar 27, 2019

Perfect for my Betta

It cleans my 5 gallon regular tap water tank and conditions it before I put my Betta fish back in the tank. I highly recommend it

Rated 5 out of 5 stars
By JCC84 on May 1, 2017

Amazing Product!

I have 4 separate aquariums and use this as a water conditioner for all tanks. I also add to the tanks when a fish is stressed/sick and when I add new fish, plants and/or decorations. Love that it comes in a pump option and that it's cheaper on Chewy.com than anywhere else. Lifetime buyer!

Rated 5 out of 5 stars
By K9LDY on Apr 28, 2017

API Stress Coat

GOOD STUFF ! IT IS THE BEST, IT IS WHAT YOU WANT TO USE to make your fish happy !!!