Common Name: red slime algae , cyano.
Scientific Name: cyanobacteria.
Red slime algae is actually not a “true” algae at all, but classified as a cyanobacteria, cyanobacteria are one of the oldest forms of life on earth and date back at least 3.5 billion years. These organisms produce oxygen as a byproduct of photosynthesis. Commonly referred to as “red slime” algae, the name cyanobacteria literally means “blue-green” algae. Despite the naming, only about half of these organisms are actually blue-green in color. Most forms found in saltwater are other colors, ranging from blackish green to blue-green, from orange-yellow to reddish-brown, and often appear deep purple to fully black in color. Starting out as small patches, it spreads out from there as a mat of sheeting covering.
Common Opinion: BAD
Lack of maintenance, and extended lighting hours are contributors that can lead to cyanobacteria problems.In addition, using RO water and a good salt mix can greatly help in reducing the chance of an outbreak. if you already have cyanobacteria in the tank, Reducing light time span and nutrients, Phosphates (PO4) and nitrates (NO3), can help reduce the cyanobacteria bloom as well as some market solution that reduce or eliminate red slime algae blooms.