API Quick Start Freshwater & Saltwater Aquarium Water Treatment, 8-fl oz bottle

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About This Item

Details

  • Contains unique, patented nitrifying bacteria that start the cycling process, so fish can be added immediately.
  • Scientifically tested to help quickly consume ammonia and nitrite,
  • Can also be used during water or filter media changes, after medicating or when ammonia and nitrite are detected.
  • Limits toxic ammonia and nitrite levels.
  • For use when adding fish or changing water or filter media.

Instructions

FAQ

Learn More About API From Our Team of Experts
Special Note
  • 4-oz bottle treats up to 110 gallons.
  • 8-oz bottle treats up to 230 gallons.
  • 16-oz bottle treats up to 470 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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Questions & Answers

9 Customer Questions

Can this be used instead of the API master test kit, which is for new aquariums, or would I have to test the tank even when using this?

What is the difference between this and API's Tap Water Conditioner?

Answer by Chewy • Jun 12, 2018
The Quick Start treatment is needed more for adding fish, water and filter media changes for an already established tank while the API Tap Water Conditioner is for beginning a brand new tank.

Can I add fish immediately after adding Quick Start to my tank?

Answer by Chewy • Apr 12, 2018
API Quick Start Aquarium Water Conditioner allows you to add your fish immediately after using.

I used when I set up my new tank. Should I put it in each 10% water change? As I plan to do this every few days for the first week or two

Answer by Chewy • Sep 26, 2019
The first time using this treatment you should shake the bottle well then add 10 ml per 10 U.S. gallons of aquarium water. For saltwater aquariums, double the dose. For maintenance you can do this once a month.
Reviews
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4.6
Rated 4.6 out of 5 stars
197 Ratings
Terms & Conditions

49 Customer Reviews

Rated 5 out of 5 stars
By Mary-Jane on Nov 30, 2025

How quickly it was delivered

I set up an aquarium and my item was delivered so fast! Thank you!

I set up an aquarium and my item was delivered so fast! Thank you!

Rated 5 out of 5 stars
By Suzanne on Jul 20, 2025

Clean Tank

I replace 1/3 of my 36 gallon tank twice a month. The Quick Start is perfect for keeping my tank at the correct levels.

I replace 1/3 of my 36 gallon tank twice a month. The Quick Start is perfect for keeping my tank at the correct levels.

Rated 5 out of 5 stars
By Marvin on Oct 12, 2025

API Quick Start

Works quickly to make water safe for fish.

Works quickly to make water safe for fish.

Rated 5 out of 5 stars
By Pattie on Aug 15, 2025

Aquarium balance

Helps to keep aquarium water safe for my Mr Blue snail

Helps to keep aquarium water safe for my Mr Blue snail

Rated 5 out of 5 stars
By Calvin on Jan 22, 2025

Works great.

Works great, for setting up tanks and getting them started right away.

Works great, for setting up tanks and getting them started right away.

Rated 1 out of 5 stars
By taveina on Jul 19, 2025

NO GOOD AT ALL

NO GOOD AT ALL

NO GOOD AT ALL

Rated 5 out of 5 stars
By Michelle on Dec 23, 2024

Great stuff

Kick starts the new water for.my better tank so I avoid the cloudiness.

Kick starts the new water for.my better tank so I avoid the cloudiness.

Rated 5 out of 5 stars
By Elizabeth on Sep 24, 2024

Results

I perform water changes every day because I have a smaller tank. I use the appropriate dose of this in the new water every day, my betta is very happy and healt

I perform water changes every day because I have a smaller tank. I use the appropriate dose of this in the new water every day, my betta is very happy and healthy.

Rated 5 out of 5 stars
By apeflames on Oct 19, 2024

Good Brand

Been using this for years. Never do a water change without it. Or start a new tank.

Been using this for years. Never do a water change without it. Or start a new tank.

Rated 5 out of 5 stars
By Vincent on Jul 31, 2024

very effective setting up new tank to allow addition of few fish after several days and used during large water changes or when adding additional livestock to cycled

very effective setting up new tank to allow addition of few fish after several days and used during large water changes or when adding additional livestock to cycled tank