Search  for anything...
API

API STRESS COAT Aquarium Water Conditioner 32-Ounce Bottle

Based on 38,804 reviews
Condition: New
Checking for the best price...
$21.88
Save $8.90 was $30.78

Buy Now, Pay Later


As low as $5 / mo
  • – 4-month term
  • – No impact on credit to apply
  • – Instant approval decision
  • – Secure and straightforward checkout

Ready to go? Add this product to your cart and select a plan during checkout.

Payment plans are offered through our trusted finance partners Klarna, Affirm, Afterpay, Zip, Apple Pay, and Google Pay. No-credit-needed leasing options through Acima may also be available at checkout.

Learn more about financing & leasing here.

Selected Option

Free shipping on this product

FREE 30-day refund/replacement

To qualify for a full refund, items must be returned in their original, unused condition. If an item is returned in a used, damaged, or materially different state, you may be granted a partial refund.

To initiate a return, please visit our Returns Center.

View our full returns policy here.


Availability: In Stock.
Fulfilled by Amazon

Arrives Sunday, Nov 1
Order within 2 hours and 26 minutes

Available payment plans shown during checkout

Protect Your Purchase

Easy claims online, fast replacements, no fees

Checking for protection plans...

At a glance

Condition
New
Size
32 fl oz
Style
Aquarium Treatment without Pump
Model
85Q
Dimensions
14.3 x 10.4 x 7.6 in; 1.1 lb
Weight
1.1 lb
Item Form
Liquid

Features 5

  • Contains one (1) API STRESS COAT Pond Water Conditioner 32-Ounce Bottle
  • Protects fish and removes harmful-to-fish chemicals from tap water to make water safe
  • Contains Aloe Vera to replace fish's protective coat damaged by handling, shipping or fighting
  • Safe for freshwater ponds, fish and pond plants, as well as surrounding wildlife and pets

Description

API STRESS COAT Pond Water Conditioner works instantly to remove chlorine, chloramines and ammonia from tap water and neutralize heavy metals. With the healing power of aloe vera, API POND STRESS COAT is also scientifically proven to reduce fish stress by 40%, which helps reduce susceptibility to disease and infection. STRESS COAT forms a synthetic slime coating and replaces the natural secretion of slime that is interrupted by handling, shipping, fish fighting and other forms of stress, as well as helping to prevent electrolyte loss. This formula is scientifically proven to heal wounds, including torn fins and skin wounds, and promote regeneration of damaged fish tissue. API POND STRESS COAT Water Conditioner comes recommended by professional fish handlers. Use this pond dechlorinator solution when adding or changing freshwater pond water, when you add new fish to your pond, and when your fish are damaged by injury or disease. With API POND products, it’s easy to keep a beautiful pond. For over 50 years, API has been creating innovative, research- driven solutions that make it easier to care for your pond. API POND Pond Treatment Supplies are designed to work in conjunction with each other to provide best results to control algae, promote healthy bacterial growth and help control and cure fish diseases and conditions such as ich and fin rot. They work to provide a safe, hospitable environment for fish such as koi, catfish, perch, goldfish and more. With API, you can spend more time admiring your fish, and less time scrubbing your pond. Make sure to use all products as directed in order to ensure the best results.

Specs 20

Brand API
Liquid Volume 32 fluid ounces
Item Weight 1.1 pounds
Item Form Liquid
Number of Packs 1
Product Dimensions 14.3 x 10.4 x 7.6 inches; 1.1 pounds
Item model number 85Q
Department Unisex-Adult

Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Sunday, Nov 1

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.

  • Klarna Financing
  • Affirm Pay in 4
  • Affirm Financing
  • Afterpay Financing
  • Zip Pay in 4
  • Financing through Apple Pay
  • Financing through Google Pay
Leasing options through Acima may also be available during checkout.

Learn more about financing & leasing here.

Top Amazon Reviews


Not Just for Fish! Also Great for Plants!
Size: 4 fl oz Style: Aquarium Treatment without Pump
I don't use this for an aquarium. In fact, I don't even have an aquarium. It was recommended by a plant expert to use in the water I use to water my plants. Hard, chlorinated water filed with chemicals is not good at all for plants and while it won't kill most of them, some of them end up unhappy over time. When I first heard about this product, I was skeptical. Could it really help with my plants? Well, upon researching, apparently so! It removes not only chlorine, which is in all tap water, it removes chloramines and heavy metals. They're all bad for fish and bad for plants as well! The price is low and I use just 2 - 3 drops with each gallon of tap water, immediately takes action. No waiting! I bought the 4 ounce size and at this concentrate, that much will last me years (and I have a lot of house plants. There's not much odor, it's clear and a little thicker than water. This is a no-brainer. I'm happy I discovered it. ... show more
Reviewed in the United States on August 2, 2026 by C.J

Great for Treating Water for Plants
Size: 16 fl oz Style: Aquarium Treatment without Pump
I bought API Stress Coat to treat and neutralize my water before using it to water my plants, and it has worked great for what I needed. It’s easy to measure and use, and I like having an easy way to condition the water before giving it to my plants. The 16 ounce bottle is a good size and should last me quite a while. It’s a simple addition to my plant care routine, and I’m glad I found it. I’ll definitely keep this on hand for future watering. ... show more
Reviewed in the United States on September 23, 2026 by Hunter80

Magic in a Bottle for Your Aquarium!
Size: 16 fl oz Style: Aquarium Treatment without Pump
Having a home aquarium can be a tricky endeavor, especially when it comes to maintaining a healthy environment for your fish. This product has been a game changer for me. Firstly, the 16-ounce size is very economical. It lasts quite a while even with regular use, which is great for someone who doesn’t want to constantly repurchase supplies. The application process is straightforward and easy – just follow the instructions on the bottle. The most impressive part is its effectiveness. Since using this conditioner, I’ve noticed that my fish are visibly healthier and more active. Their colors are more vibrant, and they seem less stressed, especially after water changes or when introducing new fish to the tank. The product claims to reduce fish stress by 40% and it really seems to live up to that promise. Another major benefit is how it treats tap water. The conditioner neutralizes chlorine, chloramines, and heavy metals present in tap water, making it safer for the aquarium. This is crucial for the wellbeing of the fish and helps maintain a balanced ecosystem in the tank. Overall, I highly recommend the API STRESS COAT Aquarium Water Conditioner to any aquarium enthusiast. Whether you’re a beginner or an experienced fishkeeper, this product is a must-have in your aquarium care toolkit. It’s a small investment for the huge benefit it brings to the health and happiness of your aquatic pets. ... show more
Reviewed in the United States on January 18, 2024 by Tye

Super Value Of Great Product
Size: 16 fl oz Style: Aquarium Treatment without Pump
I've been using this stuff for years and I usually buy local but I saw the price , already had something in my cart so I added it to save me a trip to the pet big box store . I thought I was getting the usual small bottle and when it arrived and it was 16oz I immediately thought there was a mistake . I went back and looked and it was correct . I usually get 4oz for the same price (unless on sale) locally (big box per store) and I didn't have to fight mall traffic only to search forever for a parking spot . When starting a new setup , doing a partial water change , or just adding water this stuff is a must . I add 1 gallon at a time to my 50 gallon tank and the 1 gallon mark doesn't exist but I measured out the correct amount the first few times and now just approximate it using the cap to just about double what 1 gallon calls for . It works instantly , unlike some others , so I can do the needed addition at my convenience and the fish don't seem to mind the fresh water going into the tank . No color , no change in chemical and biological balances and no smell . If you've got a fresh water tank you need this stuff . ... show more
Reviewed in the United States on August 16, 2025 by Stephen Elmore

Nice product
Size: 16 fl oz Style: Aquarium Treatment without Pump
It looks to work well. I see some bubbles in the water surface after using this product, but it may not be a real issue.
Reviewed in the United States on February 28, 2026 by Cliente Kindle

The Fish Like It
Size: 16 fl oz Style: Aquarium Treatment without Pump
We have a water garden on our deck. It holds about 7-8 gallons and we have goldfish and aquatic plants in it. The fish cannot tolerate tap water because of the purification chemicals, so we were buying spring water at the grocery store. Using API Stress Coat is much cheaper because we can now use tap water. We add .5 ml per gallon and it de-chlorinates it. Plus, it has aloe vera to help heal and fin damage and prevents stress from water imbalance. It helps promote clear water. ... show more
Reviewed in the United States on May 12, 2026 by RWS

A must have
Size: 8 fl oz Style: Aquarium Treatment without Pump
Stress Coat is wonderful stuff. One of my Orandas was laying eggs and one of my males tore off a few of the scales on her side overnight. I put her in a hospital tank with Stress Coat and she was visibly better within a few days. And within a few hours after the move she had settled down and wasn't as agitated. Definitely something every aquarium owner should have on hand. ... show more
Reviewed in the United States on July 6, 2026 by Dianne

Try it
Size: 128 fl oz Style: Aquarium Treatment without Pump
It helps with the plants that's easily to get their tits Brown it helps cut back on that and I like it.
Reviewed in the United States on August 12, 2026 by Auntbigg
Checking for best price...