How to Get Rid of Cyanobacteria – Red Slime Algae


Treating Cyanobacteria in Your Reef Tank

What is cyanobacteria? If your tank has experienced this slimy resident, don’t bow out and give up on your reef tank hobby. Humbly, the most experienced aquarist must deal with this intrusive organism and the most common reef tank pest. Although it is typically known as the red slime algae, it can also produce a variety of colors, such as black, green, and purple. Cyanobacteria is one of the oldest photosynthetic organisms. So what causes this slimy growth in your tank? It is generally perceived as an algae but this intrusive organism contains the properties of algae and bacteria.

Preventing the Growth of Cyanobacteria

blue legged hermit crabYou might be asking how and why does my reef tank get infected? A few reasons could be a spike in of phosphate and nitrate (waste), poor water circulation, and/or old light bulbs. To prevent the growth in the first place, be sure to test your tanks phosphate and nitrate levels. Maintain an adequate phosphate level at 0.05 ppm while keeping nitrate below 10 ppm. For better water circulation, be sure to eliminate any dead spots, areas where water is not moving.  You can do this by redirecting aeration, adding powerheads or rearranging rocks to entice better water circulation. Also, make sure to change the light bulbs at the recommended lifespan. If your reef tank allows, you may also consider investing in a dwarf blue leg hermit crab for keeping algae at bay, no pun intended. 

Getting Rid of a Cyanobacteria Outbreak

Now that you know how to prevent the red slime algae from growing rampant, let’s discuss how to get rid of cyanobacteria already growing in your reef tank. You have a few options: physically remove it or use chemical treatments to kill the bacteria. To remove it physically, we recommend siphon, brushing, and changing the water. It may be necessary to use a siphon brush simultaneously to remove the bacteria from large surfaces with many ridges. Maintaining a regular tank cleaning schedule is ideal to keep phosphate and nitrate levels stabilized. Alternatively, you can use a few chemicals to kill the cyanobacteria and keep your reef safe. The best recommendations are Chemiclean, Red Slime Remover, and Blue Life Red Cyano Rx.


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