7 Ways to Get Rid Of Blue-Green Algae In An Aquarium

Cyanobacteria, another name for blue-green algae, can be an annoyance and recurring issue for aquarium owners. 

This kind of algae can quickly overtake an aquarium, resulting in a murky, green, or bluish-green mess in the water. It can kill fish and other aquatic life in addition to giving the tank an ugly appearance. 

We’ll go over seven efficient methods in this in-depth guide to get rid of blue-green algae and get your aquarium back to its original state.

1. Manual removal

Manual removal of blue-green algae is one of the easiest ways to get rid of it. This entails physically clearing the substrate, ornaments, and plants off the aquarium’s surfaces, as well as any algae that may be present. This is the method for doing it.

• To remove the algae from glass walls and other hard surfaces, use an algae scraper or a clean, soft-bristled brush.
• Any plants or decorations that are significantly covered in algae should be carefully removed, and they should be rinsed in a different container filled with aquarium water.
• To remove as much algae from the substrate as you can, use a gravel vacuum.
• Do a 20–30% partial water change to get rid of any trash and algae that are suspended.

While manual removal can be time-consuming and labor-intensive, it’s an essential first step in controlling the algae bloom.

However, it’s important to note that this method alone may not be sufficient to completely eradicate the problem, as any remaining algae spores can quickly multiply and spread again.

2. Blackout Method

Blue-green algae can be removed using the blackout method, which works by denying the algae the light it needs to survive. Here’s how to put it into practice.

• To completely block off light, cover the tank with a thick, solid piece of cardboard or blanket.
• For three to five days, leave the aquarium completely darkened.
• To avoid upsetting the algae during the blackout period, refrain from feeding the fish and do as little maintenance as possible.
• After the blackout, take off the covering and give the water a thorough 50–70% change to get rid of any debris and dead algae.

By limiting the blue-green algae to the light necessary for photosynthesis, the blackout approach causes the algae to die out. 

It’s crucial to remember that fish and other aquatic life may find this technique uncomfortable, so it’s critical to keep a constant eye on the water’s conditions and offer enough aeration while the power is out.

3. UV Sterilization

One useful tool for managing blue-green algae in an aquarium is a UV sterilizer. UV sterilizers release ultraviolet radiation that damages bacteria, algae, and other microbes’ DNA, stopping them from procreating and ultimately eradicating them.

Installing a UV sterilizer in your aquarium’s filtration system requires that you follow the manufacturer’s instructions. It’s crucial to select a UV sterilizer that fits the volume and flow rate of your aquarium.

The best results are obtained when UV sterilizers are combined with the physical removal of algae and regular water changes. 

Though they might not be able to totally eradicate an existing bloom on their own, they are very good at stopping future algal blooms from developing.

4. Chemical Treatments

Blue-green algae in aquariums can be managed with a variety of chemical treatments.

When applying chemical treatments, it’s crucial to use caution, as improper application might endanger fish and other aquatic life.

UVA-H2O2, or ultraviolet-activated hydrogen peroxide, is one common chemical therapy.

In order to eliminate bacteria and algae, this procedure includes adding hydrogen peroxide to the aquarium and exposing it to UV radiation. This creates extremely reactive free radicals.

Using algaecides made especially to destroy blue-green algae, like those that include copper compounds or quaternary ammonium compounds, is an additional choice. 

Because these items can be hazardous to aquatic life in high concentrations, it is important to use them carefully and according to the manufacturer’s recommendations.

While chemical treatments can be useful in managing blue-green algae, it’s vital to remember that they should only be applied as a last resort and in conjunction with other techniques like hand removal and water changes.

5. Improved Water Quality

Blue-green algal blooms must be prevented and controlled by maintaining high water quality.

Poor water circulation and an abundance of nutrients, such as phosphates and nitrates, are ideal conditions for blue-green algae growth.

Take the following actions to enhance water quality and lessen the chance of algae blooms:

• To get rid of extra nutrients and garbage, do weekly partial water changes (20–30%).
• Utilize premium filtration devices, such as sump pumps or canister filters, to keep water circulation correct and eliminate organic waste.
• Fish should not be overfed to prevent an excessive nutritional buildup.
• To guarantee peak performance, clean and maintain your filtering systems regularly.

6. Introduce Algae-Eating Organisms

Adding creatures that consume algae to your aquarium is one sustainable and natural method of controlling blue-green algae.

By feeding on algae and slowing its growth, certain organisms—like fish, shrimp, and snails—can assist in controlling the amount of algae in the environment.

Several well-known creatures that consume algae are:

• Amano shrimp
• Nerite snails 
• Siamese algae eaters
• Otocinclus catfish
• Plecostomus 

Make sure your aquarium settings are appropriate for the long-term survival of any algae-eating species you introduce by researching their individual care needs.

Furthermore, exercise caution when adding too many algae eaters to your aquarium, as this can cause additional imbalances and issues.

7. Introduce Live Plants

A natural supply of oxygenation and biological filtration, as well as an effective means of outcompeting blue-green algae for nutrients, can be achieved by introducing living aquatic plants.

For aquariums that are prone to algae problems, plants like Amazon sword plants (Echinodorus spp.), java fern (Microsorum pteropus), and anacharis (Egeria densa) are great options. 

In addition to assisting in the consumption of surplus nutrients that would otherwise promote the growth of algae, these plants also emit advantageous substances that can prevent the growth of specific kinds of algae.

To guarantee the healthy growth of living plants, it is imperative to supply appropriate illumination, nutrient supplements, and CO2 levels.

Furthermore, keeping up with routine plant maintenance and pruning can help keep the plants from being overgrown and producing too much organic waste.

Preventing Future Blue-Green Algae Blooms

Although the above-discussed techniques can successfully remove blue-green algae from your aquarium, it’s also critical to take proactive steps to deter new blooms.

The following advice may be used to stop the growth of blue-green algae:

• Keep up a regular maintenance schedule that includes sweeping the substrate, cleaning the filters, and changing the water regularly.
• Steer clear of overfeeding and take out any uneaten food right away to avoid an accumulation of surplus nutrients.
• To prevent the growth of algae and to support the needs of your aquatic plants and occupants, make sure that the lighting levels and durations are appropriate.
• Regularly check the water’s parameters and take quick action to fix any imbalances or problems.
• Phosphate removers and algae control solutions are examples of supplements or additives for aquariums that can be used to help regulate the growth of algae.
• To establish a self-sufficient ecosystem that is in balance, incorporate living plants and organisms that consume algae.

Final Thoughts For Blue-Green Algae

Blue-green algae can be an annoying and recurring issue, but it is successfully controllable and removable with the appropriate methods and strategies. 

The growth of blue-green algae can be inhibited by creating a balanced and healthy environment that includes techniques including physical removal, blackout times, chemical treatments, improving water quality, and adding live plants and organisms that eat algae.

Never forget that the keys to handling algal problems are persistence and patience. A mix of methods and time may be needed to fully tackle the issue.

However, you can maintain the health and appearance of your aquatic inhabitants in your aquarium by adhering to the suggestions provided in this article and keeping up a proactive maintenance schedule.