{"id":13378,"date":"2022-03-28T10:40:20","date_gmt":"2022-03-28T08:40:20","guid":{"rendered":"https:\/\/recifaliste.fr\/how-to-eliminate-cyanobacteria-in-a-reef-aquarium\/"},"modified":"2026-05-06T20:39:39","modified_gmt":"2026-05-06T18:39:39","slug":"how-to-eliminate-cyanobacteria-in-a-reef-aquarium","status":"publish","type":"page","link":"https:\/\/recifaliste.fr\/en\/how-to-eliminate-cyanobacteria-in-a-reef-aquarium\/","title":{"rendered":"How to eliminate cyanobacteria in a reef aquarium"},"content":{"rendered":"\n

Discover the origins of cyanobacteria and the causes of its proliferation. Then, explore the treatments and natural methods that will help eliminate cyanobacteria in your reef aquarium. <\/p>\n\n

HOW TO RECOGNIZE CYANOBACTERIA OR BLUE-GREEN ALGAE IN A REEF AQUARIUM<\/h2>\n\n

Cyanobacteria is a single-celled organism that has inhabited the oceans for a very long time. It can appear in various colors: red, blue, green, yellow, orange, purple, or even black. <\/p>\n\n

It is capable of photosynthesis to synthesize the nutrients it needs to develop (thanks to chlorophyll). The waste product resulting from this reaction is the production of oxygen. <\/p>\n\n

In the evening,<\/strong> this production is visible on the surface. It is possible to observe vacuoles filled with oxygen forming “small” bubbles characteristic of cyanobacteria. <\/p>\n\n

Cyanobacteria under the microscope<\/h3>\n\n

Cyanobacteria is a filamentous algae; under the microscope, you can observe the typical filaments of cyanobacteria.<\/p>\n\n

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Cyanobacteria has a high proliferation potential. It is dangerous for a reef aquarium because it will literally smother benthic organisms and corals while releasing toxins that are lethal to the tank and its inhabitants. <\/p>\n\n\n\n

IMAGE: Red cyanobacteria on a grain of sand in a reef aquarium<\/em> observed under a<\/em> phase-contrast microscope<\/em> at 4x<\/em> magnification<\/em><\/p>\n<\/div><\/div>\n\n

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DANGER AND RISKS IN THE EVENT OF A CYANOBACTERIA PROLIFERATION<\/h2>\n\n

Cyanobacteria or Cyanophyceae<\/strong> is often called “red plague<\/strong>” or “blue-green algae<\/strong>” depending on the color of the cyanobacteria; this micro-algae is a benthic<\/strong> filamentous algae that has serious consequences for your reef aquarium if the proliferation is not controlled.<\/p>\n\n

Its proliferation will cause coral smothering<\/strong> in the short term and trigger RTN<\/a><\/strong> (Rapid Tissue Necrosis). <\/p>\n\n

To feed, cyanobacteria will capture organic matter with its filaments, which will then transform into phosphates. Besides the increase in phosphates harmful to the tank, the danger exists at a local level<\/strong>. Organic matter will locally release a high level of phosphate. This causes stress to the coral<\/strong>, followed by rapid tissue necrosis (RTN). <\/p>\n\n

Is cyanobacteria dangerous?<\/h3>\n\n

Yes, because cyanobacteria will produce potentially lethal toxins<\/strong> for the aquarium inhabitants. <\/p>\n\n

During its growth phase, cyanobacteria develops a toxin composed of synthesized metabolites: cyanotoxin<\/strong>.<\/p>\n\n

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Cyanotoxins<\/strong> are toxins that can become lethal to the tank’s population. They act on the regulation of dissolved salt concentrations in the internal fluids of fish and crustaceans. <\/p>\n<\/blockquote>\n\n

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HOW CYANOBACTERIA DEVELOPS IN ORDER TO STOP IT<\/h2>\n\n
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To develop, cyanobacteria needs light and draws its energy from nitrogenous, carbonaceous, and phosphorous elements.<\/p>\n\n\n\n

IMAGE: Cyanobacteria with its red filaments under a phase-contrast microscope<\/em> at 10x<\/em> magnification<\/em><\/p>\n<\/div><\/div>\n\n

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The best way to avoid facing this problem is to prevent its appearance. It is therefore necessary to control nutrient levels as well as the quality of the lighting. <\/p>\n\n

But how can cyanobacteria be eradicated in a reef aquarium?<\/p>\n\n

Here is a list of actions to prevent the appearance and proliferation of cyanobacteria in your tank:<\/p>\n\n

Beware of excess nutrients<\/h3>\n\n

We have observed that cyanobacteria appears when there is an imbalance or an excess of nutrients. This implies, at a chemical level, an excess of nitrates, phosphates, organic carbon, and sometimes even silicates. Maintaining a balanced level of nitrates and phosphates in a reef aquarium is therefore essential. <\/p>\n\n

Here are some tips for restoring a favorable NO3\/PO4 ratio:<\/p>\n\n