API Algaefix Algae Control Aquarium Solution, 8-fl oz bottle

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About This Item

Details

  • Specially developed to help treat and control algae growth.
  • May help to reduce the amount of maintenance your aquarium requires.
  • Safe enough that it can be used weekly and will not harm your fish or plants.
  • Effectively controls ldquo green water rdquo algal blooms and string or hair algae.
  • Not for use in saltwater or with freshwater crustaceans and recommended for indoor aquarium use only.

Instructions

FAQ

Learn More About API From Our Team of Experts

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

28 Customer Questions


Will it harm snails? Used a product years ago that killed off of my snails. So I'm very nervous about an algae killer. Says it safe for fish and plants...but what about invertebrates?

Answer by ChewyMar 13, 2018
This product cannot be used with freshwater crustaceans (snails).

I have a small (2 or 2-1/2 gal) tank for my Betta. How much Algaefix would I add for this tank? You say 1 ml to 10 gallons. I assume it would only be drops. Pleas advise.

Answer by ChewyJun 14, 2020
It is recommended to use 1 mL for a 10 gallon tank so you'd need approximately 0.25 mL of this solution for a 2.5 gallon tank.

Can it be used for aquatic turtles?

Answer by ChewySep 06, 2017
This can be used in a turtle habitat. Do not use in aquariums that house crustaceans such as shrimp, crabs, or lobsters.

Can this be used with API Stress Coat and is it safe for Betta fish?

Answer by ChewyJul 08, 2019
You can use API Stress Coat Aquarium Water Conditioner with all other API products. This is safe for Bettas.

4.1
Rated 4.1 out of 5 stars
216 Ratings

108 Customer Reviews



Rated 1 out of 5 stars
By Ruby on Jan 17, 2026

No

Found out it will kill my snails

Found out it will kill my snails


Rated 5 out of 5 stars
By Denise on Sep 17, 2025

This works!

Plagued with green water algae. This started clearing the aquarium within days

Plagued with green water algae. This started clearing the aquarium within days


Rated 1 out of 5 stars
By mamuka on Aug 2, 2025

The package has not arrived, it says received here, please check.

The package has not arrived, it says received here, please check.

The package has not arrived, it says received here, please check.


Rated 1 out of 5 stars
By Amber on Feb 19, 2025

Killed my fish twice

My first use of this product as prescribed on the label with API Accu Clear ended up killing my beta. I thought it was a fluke or an issue combining with the Accu

My first use of this product as prescribed on the label with API Accu Clear ended up killing my beta. I thought it was a fluke or an issue combining with the Accu Clear until I used it by itself with two tetras and it ended up killing one of them overnight as well.


Rated 5 out of 5 stars
By Beverly on Oct 10, 2025

API products are quality.

Quality aquarium products

Quality aquarium products


Rated 5 out of 5 stars
By Brian on Jun 29, 2025

Worked

Kept algae off our live rocks and cut down on the clean up

Kept algae off our live rocks and cut down on the clean up


Rated 1 out of 5 stars
By Alma on Apr 4, 2025

Trying it for the first Time

Not sure yet. I love API Products so I'm confident it will work in my pond. Follow the directions always.

Not sure yet. I love API Products so I'm confident it will work in my pond. Follow the directions always.


Rated 5 out of 5 stars
By Elijah on May 5, 2025

It actually works

It cleared the algae rite up, only took a couple days.

It cleared the algae rite up, only took a couple days.


Rated 5 out of 5 stars
By Ronald on May 3, 2025

Speed of delivery

Very Speedy, Accurate and at a very Reasonable Cost

Very Speedy, Accurate and at a very Reasonable Cost


Rated 4 out of 5 stars
By Big on Jan 11, 2025

Works great

Little powerful though. Make sure you know what kind of algae you're working with

Little powerful though. Make sure you know what kind of algae you're working with