How to Remove Cyanobacteria in Aquariums?

 

They are crucial in shaping our planet's atmosphere and ecosystems by producing oxygen through photosynthesis. Unlike true algae, which are eukaryotic organisms, cyanobacteria are prokaryotes, meaning they lack a defined nucleus and other membrane-bound organelles. They are found in many aquatic environments, from freshwater lakes and rivers to marine systems and extreme habitats such as hot springs and deserts. Cyanobacteria can exist as single cells, colonies, or filaments, often forming visible mats or blooms on the water's surface. 

Despite their ecological importance, cyanobacteria can cause significant problems when they proliferate excessively in aquatic systems, a phenomenon often driven by nutrient pollution (mainly nitrogen and phosphorus) from agricultural runoff, wastewater discharge, and other human activities. These blooms can produce harmful toxins known as cyanotoxins.

Causes of Cyanobacteria in Aquariums

Cyanobacteria outbreaks in aquariums are primarily driven by environmental factors that create favourable conditions for their growth. Understanding these causes is essential for preventing and managing cyanobacteria issues effectively. Here are the key factors that contribute to the proliferation of cyanobacteria in aquariums:

Excess Nutrients

One of the most significant causes of cyanobacteria growth is the presence of excess nutrients, particularly nitrates and phosphates. These nutrients can accumulate in aquariums due to overfeeding, decaying organic matter, and inadequate maintenance. When fish are overfed, uneaten food settles and decomposes, releasing nutrients into the water. 

Similarly, plant debris and waste from fish and other inhabitants contribute to nutrient buildup. High nutrient levels provide a rich environment for cyanobacteria to thrive and outcompete other microorganisms.

Inadequate Water Flow

Cyanobacteria tend to flourish in areas with low water circulation or stagnant water. Insufficient water movement allows organic debris and nutrients to settle, creating localized pockets where cyanobacteria can establish and grow. Aquariums with poor filtration or inadequate circulation pumps are susceptible to cyanobacteria outbreaks. 

Ensuring proper water flow throughout the tank helps distribute nutrients more evenly and prevents the formation of stagnant zones.

Inconsistent Lighting

Lighting plays a crucial role in the growth of cyanobacteria, as they rely on light for photosynthesis. Excessive or irregular lighting schedules can encourage their proliferation. Continuous exposure to sunlight or lighting that exceeds the needs of the aquarium’s inhabitants can stimulate cyanobacteria growth.

Additionally, using low-quality or outdated lighting systems can contribute to an imbalance, favoring cyanobacteria over other beneficial organisms.

Low Oxygen Levels

Cyanobacteria can thrive in low-oxygen environments, often outcompeting other aerobic bacteria and algae. Poorly oxygenated water can result from overstocking, inadequate aeration, or insufficient water movement. Cyanobacteria have a competitive advantage when oxygen levels drop and can spread rapidly. Ensuring proper aeration and maintaining an appropriate stocking level helps keep oxygen levels stable and supports a balanced ecosystem.

Introduction from External Sources

Cyanobacteria can be inadvertently introduced into an aquarium through contaminated water, plants, substrates, or decorations. When new items are added to the tank without proper quarantine or cleaning, they can bring cyanobacteria spores. To minimize the risk of introducing cyanobacteria, it is essential to rinse and, if possible, quarantine new plants and decorations before adding them to the aquarium.

Identifying Cyanobacteria

Recognising cyanobacteria is crucial for effective treatment. Key characteristics include:

• Slimy, often smelly mats that can be easily peeled off surfaces. 
• Colours range from blue-green to black. 
• Rapid growth and ability to cover large areas in a short time. 

Prevention Strategies

Preventing cyanobacteria is often easier than dealing with a full-blown outbreak. Here are some preventive measures: 

Maintain good water quality 

Regular water changes

Perform consistent water changes(10-20% weekly) to remove excess nutrients and organic matter.

Avoid Overfeeding

Feed fish only what they can consume within a few minutes to reduce uneaten food and waste. 

Use Quality Food

Opt for high-quality fish food with low phosphate content to minimize nutrient buildup.

Optimize water flow

Proper filtration

Use a reliable filtration system to maintain water clarity and remove debris. 

Circulation Pumps

Install circulation pumps to ensure adequate water movement throughout the tank, preventing dead spots where cyanobacteria can thrive. 

Regulate lighting 

Consistent Lighting Schedule

Set a consistent lighting schedule (8-10 hours daily) to avoid excessive light exposure. 

Adjust Light Intensity

Adjust the light intensity to suit the needs of your aquarium's inhabitants without promoting cyanobacteria growth.

Eradication Methods

If cyanobacteria have already established themselves in your aquarium, several methods can help eliminate them:

Manual Removal 

Vacuuming

Use an aquarium vacuum to remove cyanobacteria mats during water changes. 

Scraping 

Gently scrape off cyanobacteria from surfaces using an algae scraper or a soft brush. 

Chemical Treatments 

Antibiotics

Products containing erythromycin can be effective against cyanobacteria. However, use caution as antibiotics can harm beneficial bacteria and disrupt the aquarium's biological balance.

Algaecides

Some algaecides specifically target cyanobacteria. Follow the manufacturer's instructions carefully to avoid harming other aquarium inhabitants.

Natural Methods

Blackout

Completely cover the aquarium to block all light for 3-4 days. This can starve cyanobacteria of light, hindering their growth. Ensure adequate oxygenation during this period.

Beneficial Bacteria

Introduce beneficial bacteria products to outcompete cyanobacteria for nutrients. 

UV Sterilizers 

Installation

Install a UV steriliser in your aquarium's filtration system. UV light can kill free-floating cyanobacteria and prevent their spread.

Maintenance

Regularly clean and replace the UV bulb to ensure optimal performance.

Long-Term Management 

Eradicating cyanobacteria is only part of the solution. Long-term management is crucial to prevent recurrence: 

Monitor Nutrient Levels 

Test Water Regularly

Test kits should be used to monitor nitrate and phosphate levels, keeping them within acceptable ranges.

Use Phosphate Removers

Consider using phosphate-removing media in your filter to control phosphate levels.

Maintaining a Healthy Ecosystem 

Balanced Stocking

Avoid overstocking your aquarium to reduce waste production and nutrient buildup. 

Healthy Plants

Cultivate live plants that can outcompete cyanobacteria for nutrients. Fast-growing plants like water wisteria, hornwort, and duckweed can be particularly effective.

Educate Yourself

Stay Informed

Keep up with the latest aquarium care techniques and trends through reputable sources.

Seek Advice

Join aquarium forums or local clubs to share experiences and gain insights from fellow aquarists.

People Also Ask

What chemical kills cyanobacteria?

Chemical substances called algaecides are sprayed on water to eradicate cyanobacteria and end the bloom. Below are a few instances: algaecides based on copper (copper citrate, copper sulphate, copper II alkanol amine, etc.) and potassium permanganate.

Why does my tank have cyanobacteria?

A nutrient imbalance can cause cyanobacteria outbreaks in planted aquariums, like actual algae outbreaks. In several cases, the cause was found to be a high phosphate level, occasionally in conjunction with a nitrogen deficiency (more precisely, a nitrate defect).

How do I fix cyanobacteria in my aquarium?

• Dim the light.
• Partial variations in water.
• Physical extraction.
• Thoroughly clean the tank.
• Use filter pads or water treatments that remove phosphates.
• Add 10 gallons of water and 200 mg of erythromycin.

Conclusion

Cyanobacteria can be a challenging problem in aquariums, but they can be controlled and eradicated with a thorough understanding of their causes and effective management strategies. By maintaining wood water quality, optimising water flow, regulating lighting, and employing both manual and chemical treatments when necessary, aquarists can keep their tanks free from cyanobacteria and provide a healthy environment for their aquatic inhabitants. 

Remember, prevention is always better than cure, so adopting proactive measures is critical to avoiding cyanobacteria outbreaks in the first place.