Silica Algae or Brown Algae is an algae species which thrives in saltwater environments. Once established, it can spread quickly throughout an aquarium’s interior forming thin dark brown coatings which cover most surfaces in its path.
Problematic algae blooms can be especially common among new aquariums, which may cause cause alarm for newcomers. Luckily, this issue can usually be handled easily; most often it can simply be removed without too much difficulty. It’s also relatively straightforward to prevent future outbreaks if you understand their source – taking preventative steps will keep your tank looking beautiful without any sign of green slime growth!
Phaeophyceae are true Brown Algaes that belong to the Class Phaeophyceae, comprising an expansive group of multicellular algaes found throughout cold marine waters, such as Kelp. But these types of brown-colored algaes won’t grow in your aquarium!
Golden Algae (Class Chrysophyceae), are an abundant group of yellow-brown algae found predominantly in freshwater environments and an important contributor to food web dynamics of freshwater ecosystems. As single-celled organisms with cellulose cell walls similar to plants and flagellated tails for propulsion, these aquatic creatures typically remain suspended within the water column rather than inhabiting home aquariums.
However, another type of algae that thrives in aquatic environments and appears brown under artificial lighting conditions in an aquarium environment is commonly known in the trade as Brown Algae or Silica Algae.
What Is Silica? Silicon is a basic and abundant element, which when combined with oxygen forms the compound Silica which forms the basis for such materials as sandstone, quartz and glass. Since Silica can easily be found in aquatic environments it has been widely adopted by single-celled organisms to form protective outer “clamshells.” These organisms are commonly referred to as diatoms.
Brown Silica Algaes (Diatoms) “Brown Algae” is the common name given to diatoms belonging to Class Bacillariophyceae that are found both freshwater and saltwater home aquariums. Diatoms are single-celled organisms which may exist either singly or as colonies, giving this common name its origins.
Diatoms, like plants and other algaes, convert light energy to fuel their cells. Each species forms its own beautiful opaline crystal cover to its cell wall that resembles snowflakes under a microscope – serving both as aesthetic protection for these microscopic organisms and as significant armor against potential threats.
Planktonic species found in open waters typically depend on turbulent churning of the upper water to remain suspended; however, most diatoms are non-motile organisms due to their relatively heavy cell walls causing them to quickly sink to the bottom and create an invisible film at its base.
Are the Dangers of Brown Algae Realized by Your Fish?
Brown Algae diatoms will generally not harm your fish if kept under control, though some species do feed off of these diatoms, helping clean out your tank by eating the diatoms that collect there. Brown Algae however is usually detrimental in an aquarium environment and should be avoided at home aquarium environments.
Diatoms differ from blue-green algae in that they do not adhere together into large slimy sheets, instead appearing scattered and patchy throughout your tank’s environment. Patchy formation of diatoms usually makes your aquarium appear less appealing.
Causes of Brown Algae
Brown algae can quickly take over a newly setup aquarium. Dark environments are especially susceptible to developing brown algal blooms as plants and green algaes compete for nutrients needed by diatoms that provide life support to diatoms.
Brown algae blooms are a sure sign that the water chemistry in your aquarium is out of balance, and should be your top priority after providing proper lighting. Possible causes may include excess silica or nitrate in the water as well as too many nutrients in general.
Silica deposits in aquariums may arise from tap water high in silicic acid or leached from substrates containing silica such as silica sand. If this problem continues, and Brown Algae persists, consider investing in special silicate-absorbing resin for your filter system to address this problem.
Nitrates that feed diatoms may not only accumulate from tap water sources, but can also come from sources like food waste, decaying matter, or overstocking fish tanks. By increasing water changes to remove excess nitrates from your system, diatoms’ growth will slow considerably.
Removing Brown Algae
Diatoms that rest at the bottom make cleaning up Brown Algae an easy process; no scrubbing is needed as this type of algae does not adhere strongly to tank surfaces and can easily be wiped away with soapy water or by wiping down decorations that might have become affected before vacuuming off any remaining gravel from inside your aquarium.
Removal can be the hardest part, but using a vacuum to quickly remove it from the gravel will do just fine. Regular vacuuming also ensures the algae won’t grow back as rapidly in future months and years.
Freshwater aquariums can benefit from adding sucker-mouth fish that feed on brown algae, such as plecostomus or several otocinclus catfish. Saltwater tanks offer many other species capable of eating diatoms; many species of fish and invertebrates act as diatom grazers themselves.
Preventing Brown Algae
Lighting should provide at least eight hours of illumination per day in a tank. As your tank matures, brown alga may be naturally eliminated through competition between plants and green algae for nutrients in the water such as nitrites and nitrates.