Treating Black Beard Algae With Hydrogen Peroxide in a Aquarium

Some amount of algae is normal in most fish tanks, but when you see algae that is short, thick, and nearly black, it’s likely you’re dealing with the dreaded black beard algae.

Once you see these stubborn algae, it’s important to treat them right away.

Treating Black Beard Algae With Hydrogen Peroxide in a Aquarium

Black beard algae, also known as BBA, is one of the most frustrating types of algae that can infest your tank. It grows on decor and plants, and can slowly kill your plants over time.

Thankfully, black beard algae can be treated with something that most people have right in their medicine cabinet: hydrogen peroxide. 

Treating Black Beard Algae With Hydrogen Peroxide

Black beard algae can be treated with 3% hydrogen peroxide without causing any damage to your plants or fish, as long as it’s used correctly.

How Do You Kill Black Beard Algae With Hydrogen Peroxide?

Black beard algae can be killed by either spraying or soaking it in hydrogen peroxide.

Both spraying and soaking are adequate ways of treating the black beard algae, but spraying can be gentler on some delicate plants.

For hydrogen peroxide spray treatment:

  • Remove the decor or plant that has the black beard algae on it from the tank.
  • Spray the item with 3% hydrogen peroxide.
  • Let the hydrogen peroxide sit for 3 to 5 minutes.
  • Thoroughly rinse the plant or decor off with clean water until all the hydrogen peroxide is removed before placing it back in the tank.

For hydrogen peroxide soaking treatment:

  • Remove the decor or plant that has the black beard algae on it from the tank.
  • Soak the item in 3% hydrogen peroxide for 3-5 minutes.
  • Remove the decor or plant from the hydrogen peroxide and thoroughly rinse off all the chemical before returning it to the tank.

When you replace the treated item, the algae will still be present since it sticks so stubbornly, but it will now die off.

After you replace the treated item, you may notice the black beard algae turning colors from black to pale gray or even light red. This simply means the black beard algae are dying, and you’ve accomplished your goal.

YouTube video

How Much Hydrogen Peroxide Is Needed?

When outside of the tank, you can spray the black beard algae or soak it in as much hydrogen peroxide as you need.

Adding hydrogen peroxide to the fish tank itself isn’t recommended because it can kill other plants as well as algae. If there is no way to remove the item that the black beard algae are growing on, you can add 10mls of hydrogen peroxide for every 15 gallons of water in the fish tank.

jbarr3tt1979

Hello, I'm Jason. I'm the guy behind HelpUsFish.com. I volunteer at my local fish shop and I created this site to offer tips and advice on the fish I care for.

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