Instructions
Identify your enemy. Cyanobacteria form a slimy blue-green or red film in your aquarium. The organism quickly grows given the proper conditions and can spread throughout your fish tank. Remove any signs of cyanobacteria immediately and begin preventive measures to stem continued growth.
Replace your aquarium light bulbs. Algae grow at wavelengths between 665 to 680 nanometers (nm). Cyanobacteria grow at these wavelengths and at shorter wavelengths such as 525 and 620 nm. Adjust the spectrum and intensity of your light source to fight repeated cyanobacteria growth. Turn off your lights altogether for several days to deprive the cyanobacteria colonies of a needed food source.
Change your aquarium water frequently. Check the nitrate levels in your tank and keep them less than five parts per milliliter. Use a protein skimmer to keep your aquarium clean.
Avoid tap water and use deionized or reverse osmosis water to stop cyanobacteria growth.
Feed your fish every other day to reduce debris in your tank.
Try antibiotics to fight cyanobacteria if other methods fail. Visit an online aquarium store such as Aqua Direct or your local pet store to find aquarium medications such as "AB Anti Red 100ml" to fight blue-green algae.
How to Battle Cyanobacteria
Blue-green or red-slime algae are one of the oldest organisms on the planet. They are bacteria known as cyanobacteria and they grow in salt and fresh water and feed on light and nitrogen. Cyanobacteria grow in reds, black and blue-green colors and can quickly spread in an aquarium. Battle cyanobacteria when it first appears to prevent it from taking over your fish tank.