How To Get Rid Of Blue-Green Algae In A Planted Aquarium

Last Updated on September 11, 2021 by Marco C.

To help keep your fish tank pristine, you will want to know how to get rid of blue-green algae in a planted aquarium. Though algae in a tank is normal, blue-green algae can be problematic. It is important to take proper care of your fish tank in order to minimize the amount of algae.

Blue-green algae can be harmful to fish and in some cases can even be deadly. For a healthy environment in a tank, it is important to rid your tank of blue-green algae. Fortunately, there are multiple ways you can keep your tank free from this issue.

What Is Blue-Green Algae?

Blue-algae, also known as cyanobacteria, is a phylum of photosynthetic bacteria that is found in water and soil. It has a structure that can be unicellular to filamentous or with some species being colonial. It grows quickly and covers substrate in aquariums.

Blue-algae has a slimy consistency and often an unpleasant, fishy odor. In some cases, a severe overgrowth can cause foamy scum on the surface of the tank. Though most commonly it is blue-green in color, it can also be greenish-brown, black, or even red.

Though blue-green algae can be harmful to fish, it is often not deadly, though in rare cases it can be. However, cyanobacteria in a freshwater aquarium can be deadly to the live plants in your fish tank.

What Causes Blue-Green Algae In Aquariums?

There are a few different causes of blue-green algae in aquariums. Fortunately, they are often preventable with the right care. Generally, blue-green algae tend to thrive in warm, slow-moving water that is full of nutrients.

Too Much Light

Light allows algae to thrive. If you have your tank located in an area with direct sun, you will likely have more algae growth.

Dirty Tank

A dirty tank has all the makings to let algae grow. When waste, such as leftover food and fish waste, has the chance to become stagnant, it allows for algae to bloom. Blue-green algae are often able to thrive in a dirty fish tank, as it has all the right conditions for growth.

Not Enough Current

When the water is too still, algae are able to grow in several places. With not enough current in the water, waste can settle and give the tank the right environment for algae to take form.

New Plants

If you have recently added new live plants to your aquarium, they may have blue-green algae on them. The algae can then quickly spread throughout the tank. Be sure to inspect your new plant before adding it to your aquarium for blue-green algae.

How To Get Rid Of Blue-Green Algae In A Freshwater Aquarium

Once cyanobacteria have formed in your fish tank, it can be tricky to get rid of the problem. Cyanobacteria in an aquarium can be frustrating to deal with. It is important that you take all the proper steps to ensure you properly deal with the blue-green algae problem.

Cyanobacteria is particularly common in new aquariums, but can also occur at any point. Due to its hardiness, it is able to live in harsh environments. With no intervention, blue-green algae will just continue to grow and spread in your aquarium.

Clean The Tank, Scrub The Rocks, Plants and Vacuum The Gravel

To allow your fish and plants to have a healthy environment, it is important to keep your tank clean. Clean your tank on a weekly basis in order to get rid of excess waste.

When cleaning, scrub your rocks and plants to clean them off. You can use a toothbrush to scrub away at the cyanobacteria. In addition, you should vacuum the gravel, as waste tends to get trapped between the pieces.

get rid of blue green algae

Learn more about: What Makes Aquarium Water Cloudy?

Change The Water

Regular water changes are key to a healthy tank. If you have noticed blue-green algae in your tank, perform a water change of 20% for three straight days. On the fourth day, perform a water change of 10-15%.

Turn Off The Tank Lights and Avoid Direct Sunlight

When you have spotted blue-green algae, turn off the tank lights for three days. It is important to take the light source away as algae thrive in light. In addition, avoiding keeping your aquarium in an area that receives direct sunlight.

Use Water Conditioner

Phosphates can help contribute to algae growth. By using a water conditioner, you can help regulate the phosphate levels to minimize the chance of cyanobacteria forming.

Improve Water Flow

Algae love stagnant water. By improving the water flow, you can help prevent blue-green algae from forming. Make sure to regularly clean your filter using aquarium water and if need be, buy a stronger filter to improve the flow.

Avoid Over-Feeding and Over-Population

When over-feeding, the leftover food can create a dirty environment as it dissolves. In addition, too many fish in your tank leads to an excess of waste. Be sure to not overcrowd your tank or overfeed your fish in order to prevent excess waste which can encourage algae growth.

Storebought Products

If the at-home treatments you tried didn’t work, you can buy storebought products to rid your aquarium of cyanobacteria. Products such as Chemiclean and Seachem Pristine are designed to eliminate blue-green algae from your fish tank. Be sure to properly read the instructions to ensure that the specific product is safe to use in your tank.

The Importance Of Knowing How To Get Rid Of Blue-Green Algae In A Planted Aquarium

Blue-green algae can causes problems for your fish and plants in your aquarium. In addition, it has an unpleasant appearance and smell. Once it grows in your tank, it can be tricky to get rid of.

Be sure to regularly clean your aquarium, including the gravel, rocks, and plants. Regularly change out your water and make sure you have a properly working filter that is strong enough. Avoid keeping your aquarium in direct sunlight and don’t over-feed or over-populate your fish tank.

Do you have any questions about how to get rid of blue-green algae in a planted aquarium? If so, please ask your blue-green algae-related questions in the comment section down below.

Read more about: How To Remove Ammonia From Aquarium Water

Leave a Comment