Hydrogen Peroxide Aquarium Dosage & 3 Best Ways To Use It

Last Updated on October 21, 2022 by admins

Hydrogen peroxide is commonly used as a disinfectant for many different disease-causing organisms. Stay tuned and learn all about hydrogen peroxide aquarium dosage.

Hydrogen peroxide (H202) is a weak acid that has strong oxidizing properties and is used as a treatment against many different disease-causing organisms such as parasites, bacteria, and fungi. Unlike other chemical compounds used for disinfection and cleaning, H202 will be converted to harmless water and oxygen after 24 hours in contact with water, making it the perfect solution for use in such a delicate environment as an aquarium.

Keep reading and find out everything you need to know about hydrogen peroxide aquarium dosage.

What is Hydrogen Peroxide?

Hydrogen peroxide is a weak acid characterized by its strong oxidizing properties. In its pure, concentrated form, it is a pale blue liquid that is slightly more viscous than water. However, when it is diluted, it appears completely colorless.

As for use, it is used as an oxidizer, bleaching agent, and antiseptic, and can also be found in various forms ranging from 1-90% H2O2. Keep in mind that all concentrations higher than 20% can be corrosive and harmful to your hands.

Although a potent and a bit toxic chemical, you can still use it in your tank. It is only important to pay attention to the fact that you have proper hydrogen peroxide aquarium dosage. You will find more about it below.

 Can I put hydrogen peroxide in my aquarium?

What Can Hydrogen Peroxide Do in an Aquarium Tank?

In terms of composition, hydrogen peroxide consists of water and an extra oxygen molecule, when added to water it breaks down into water and oxygen. Accordingly, it can be used as a source of extra oxygen for your aquarium pets. However, be careful as high concentration can cause retarded growth and destroy the fish gills leading to your fish’s death.

In addition, H2O2 can be used for spot treatment in ornamental aquarium fish, as it can knock off flukes, protozoans, as well as fungi, and bacteria in the gills and bodies of aquarium animals.

6% Laboratory-Grade Hydrogen Peroxide, 3.8L

Hydrogen peroxide aquarium dosage; Algae treatment

If your aquarium is infested with stubborn algae, most hobbyists will recommend using H2O2 as the perfect treatment to solve the problem. It is quite popular in treating tanks that are attacked with major algae growth; there is no form of algae that can survive this type of treatment. As for hydrogen peroxide aquarium dosage, it depends on the algae species.

Thus, for example, for blue-green algae infestation, it is recommended to use 8-15 ml of the 3% solution of hydrogen peroxide per 50 liters of water. On the other hand, 25-35 ml of 3% hydrogen peroxide solution per 50 liters of water is recommended for green algae infestation.

 How long does hydrogen peroxide last in an aquarium?

Many hobbyists, especially beginners, are often confused by arithmetic, so we will explain it to you briefly. So, you need to divide the gross volume of your aquarium tank by 50 and then multiply that number by the lowest recommended dose for a 3% hydrogen peroxide solution, depending on the type of algae you are fighting.

The aquarium tank has a capacity of 300 liters and you are struggling with blue-green algae.


According to the data obtained, 48 ml of H2O2 is needed to treat this aquarium tank from infestation.

Take a look at this article as well.

Hydrogen peroxide aquarium dosage; Plant dip

Since H2O2 is a natural bleaching agent that is safe to use on almost every species of ornamental aquarium plant, we will show you how to use it in that case as well.

You must first clean your aquarium plants of debris and any other dirt that may be found on them. After you do this, you need to mix hydrogen peroxide with water, the recommended ratio is 2-3 ml of hydrogen peroxide per gallon of water in a bucket large enough to hold all your plants.

You are then free to dip your aquarium plants into the solution. Ensure not to damage the plant’s leaves while dipping it! Less sensitive plants can be in solution for a maximum of 5 minutes, while more sensitive ones only about 2 minutes. Then simply rinse them under cold running water until all the hydrogen peroxide is removed from the leaves.

Hydrogen peroxide aquarium dosage; Tank disinfection

If you are considering disinfecting the tank to get rid of fungi and bacteria, simply use 1.5 ml of hydrogen peroxide per 4 liters of water. The procedure is also simple. Turn off the filters and spread 3% hydrogen peroxide on the surface of the water and gently stir it. Leave the aquarium to stand for about an hour and then turn the filters back on.


The most important thing of all is to always read the safety instructions before use, to be sure that you will not cause any harm to your aquarium pets or plants. In addition, don’t forget to wear protective gear and avoid direct contact with skin, eyes, and clothing. –
You know the saying, prevention is better than cure.

That would be it, now you know all about hydrogen peroxide aquarium dosage. If you have any questions, please let us know in the section below.

You may also be interested in How To Raise Alkalinity In The Aquarium; The Fastest And The Most Reliable Solutions.

 hydrogen peroxide aquarium dosage



How Much Hydrogen Peroxide Is Safe For Fish Tank?

The recommended and proven safe concentration for use in aquariums is 0-3% H2O2 solution.  

Can I Put Hydrogen Peroxide In My Aquarium?

You can use hydrogen peroxide in your aquarium. It is a great way to solve the problems of flukes, protozoa, as well as fungi and bacteria.


Will Hydrogen Peroxide Hurt Fish?

When used in the correct concentrations and proportions, H2O2 will certainly not cause any harm to your aquarium pets.


How Long Does Hydrogen Peroxide Last In An Aquarium?

Once in contact with aquarium water, hydrogen peroxide will turn into harmless water and oxygen after only 24 hours.