Added by on August 22, 2013

The Algae Thread

Green Algae

Other Names: Hair or Spot Algae
Color: Green
Appearance: Circular, thin, bright green spots that adhere strongly to the surface of the glass and other hard surfaces.

•   Excess light
•   Excess nutrients

Green spot is a very common algae that is often seen in home aquaria. A small amount of these types of green algae are normal and expected in any aquarium.

•   Scrub or scrape off surfaces

Spot algae can only be mechanically removed. Sharp objects should not be used in acrylic aquariums. Instead use a plastic razor, cloth pad, or a very gentle scouring pad. On glass tanks, scraping with a razor blade is very effective.

•   Regular water changes
•   Regular aquarium cleaning
•   Avoid overfeeding fish

Regular tank cleaning and water changes is the best preventative measure. Never the less, it is still quite normal to see small amounts of this type of algae. Prompt attention to sudden algae overgrowth growth will prevent more serious problems.

Brown Algae

Other Names: Gravel algae, Silica algae
Color: Brown
Appearance: Brown algae begins as brown patches on the gravel and/or glass, then rapidly coats most surfaces of the aquarium with a thin, dark brown coating that is easily removed. Unlike blue-green/slime algae, it does not come off in large slimy sheets.

•   Excess silicates & nitrates
•   Inadequate light
•   Low oxygen levels

Brown algae is a common occurrence in a newly set up aquarium. It is generally caused by too little light, an excess of silicates, an abundance of nutrients, and too little oxygen. Silicates can build up through tap water that is high in silicic acid, and silicates that leech from some types of substrates.

•   Wipe off surfaces & vacuum gravel well
•   Use silicate adsorbing resin in the filter
•   Increase the lighting
•   Stock a plecostomus or several otocinclus

This type of algae does not adhere strongly to the tank surfaces, and is easily wiped away. Vacuuming the gravel with a siphon will quickly remove coatings from the substrate. Increasing the lighting will inhibit re-growth of brown algae. As a new tank matures brown algae is often eliminated naturally by plants and green algae competing for nutrients.Some sucker-mouth catfish will readily eat brown algae, most notably plecostomus and otocinclus. If the problem is due to high silicates in the water, and the brown algae persists, a special silicate absorbing resin can be used in the filter.

•   Use of RO water
•   Regular water changes
•   Regular aquarium cleaning
•   Good lighting

As with any algae, keeping the tank clean and performing regular water changes is one of the best preventative measures. Unfortunately it is still possible to get algae in spite of regular maintenance, especially in a newly established aquarium. Prompt attention to sudden algae growth will prevent more serious problems.

Cyanobacteria aka Blue-Green Algae

Names: Cyanobacteria, Blue-Green Algae, Slime Algae, Smear Algae
Color: Blue-green, may also be brown, black or red.
Appearance: Cyanobacteria, often called Blue-Green Algae, grows quickly and will cover all surfaces in the aquarium in short order.  When disturbed it comes off in sheets.  It is also called Slime or Smear Algae, which is an appropriate name as it is very slimy and often gives off an unpleasant swampy or fishy odor. A severe overgrowth of Cyanobacteria can gather into foamy scum at the surface of the water. It is typically blue-green in color, but it can be greenish-brown to black, or even red in color.

•   Cyanobacteria organism introduced to the tank
•   Excess Light
•   High levels of organic wastes
•   Anaerobic conditions

Also referred to as Slime or Smear Algae, Blue-Green Algae is not truly an algae. Instead it is Cyanobacteria, an the organism that lies somewhere between algae and bacteria. Overgrowth of this organism generally occurs when there are high levels of dissolved wastes and nutrients in the water, such as nitrates and phosphates. Phosphates in particular, are a prime contributor to overgrowth of Blue-Green Algae

The buildup of excess nutrients and dissolved waste may be due to lack of water changes and regular maintenance, overfeeding, or because the tank is new and the beneficial bacterial colonies have not become established. However, because Cyanobacteria can fix its own nitrogen, it can appear even in a well maintained matured tank.

•   Reduce light
•   Partial water changes
•   Physical removal
•   Clean tank well
•   200 mg erythromycin phosphate/10 gallons water

Once established, Blue-Green Algae is rather difficult to eradicate. One means to eliminate it is by taking steps to reduce the nutrients and mechanically removing the algae itself.  Start by scraping the glass, scrubbing the rocks and plants, and vacuuming the substrate. Perform a partial water change of 15-20% and turn the lights in the tank off for three days. On the fourth day turn the lights back on and perform another 10-15% water change. That should get rid of the algae overgrowth and reduce the elevated wastes and nutrients that support its growth. If there is still Blue-Green Algae growth, the process should be repeated.

Be aware that the algae will soon return if the underlying causes are not corrected permanently. In fact, it can never truly eliminated. However, regular water changes and maintenance will eliminate the re-occurrence of an overgrowth of Blue-Green Algae. Follow the steps listed in the prevention section to ensure re-growth doesn’t occur.

Another treatment option is Erythromycin, which will kill he Cyanobacteria that causes the slimy growth. However, use of Erythromycin can also affect the beneficial bacteria in the aquarium, and should be used with care. If such treatment is used, monitor ammonia and nitrite levels closely for several weeks.

Note: Algae eaters do not eat Cyanobacteria.

•   Avoid overfeeding fish
•   Avoid excess light
•   Regular water changes
•   Regular aquarium cleaning

As with any algae, keeping the tank clean and performing regular water changes is one of the best preventative measures. When water changes are not routinely performed, nitrates and phosphates will rise, which encourage algae growth of all types. Performing small water changes every week or two will keep nutrient levels low.

Overfeeding is one of the biggest causes of excess nutrients in the water that subsequently cause algae growth. Most fish do not need more than one feeding a day, and then only feed an amount that will be eaten in a few minutes. If food is visible on the bottom after ten minutes, you are overfeeding your fish.  Excess light, particularly direct sunlight, is another common cause of algae growth. Avoid placing a tank where it will get direct sunlight.

Unfortunately it is still possible to get algae in spite of regular maintenance. In fact, small amounts of algae growth is normal. Prompt attention to sudden algae growth will prevent more serious problems.

Beard Algae

Other Names: Bear algae, Red Beard, Purple Beard and Black Beard
Color: Bright green to blue-green to blackish green to red
Appearance: Belonging to the red algae family, beard algae grows on the edges of plant leaves as well as on the edges of almost any hard surface. Composed of very fine strands it grows in dense patches resembling a dirty green beard, thus earning the name beard algae. Rapid growing, it is soft and slippery, yet clings tenaciously to plants and cannot be easily removed by hand. It is eaten by only a few fish, notably the Florida Flag Fish and the Siamese Algae Eater (Crossocheilus siamensis).

•   Rhodophyta
•   Contaminated plants
•   Small strands in water of fish bag
•   Digestive tract of fish
•   Too much or too little carbon to light ratio

Beard algae most often enters the tank on contaminated plants, however even small free floating strands in a bag with fish are enough to start it growing in your aquarium.

•   Bleach affected plants
•   Remove affected leaves
•   Stock tank with Siamese algae eater
•   Treat tank with copper

Affected plants can be soaked for two to three minutes in a ten percent bleach solution to kill any algae on them. Completely remove heavily affected leaves. Bleach rocks, gravel, and any other items that exhibit growth of the algae. Stock the tank with a Siamese algae eater (Crossocheilus siamensis).

Note: Be sure to purchase the proper species, as many species of fish are sold under the name of Siamese algae eater. Other species of fish do not eat beard algae. If other options fail, treat with copper according to manufacturers directions. However, copper can have adverse effects on certain plants as well as fish, and should be used with caution.

•   Quarantine new fish for 48 hrs
•   Purchase plants & fish from reputable LFS
•   Bleach new plants prophylactically

To avoid algae entering the tank via fish, quarantine new fish for at least two days. When placing them in the tank net the fish rather than dumping them out of the bag, so no bag water enters your tank. Soak newly purchased plants for two to three minutes in a ten percent bleach solution to kill any algae on them.

Green Water 

Other Names: Algae bloom
Color: Green tinted water
Appearance: The water itself turns green. In severe cases the water may be so green that the fish are not visible.

•   Suspended microscopic algae
•   Excess light, especially direct sunlight
•   Too many fish
•   Excess nutrients
•   Excess wastes

Green water is usually due to either a significant excess of light (particularly direct sunlight), or a major water quality problem. Although it may look terrible, it is not toxic to fish.

•   Blocking out light completely
•   Diatomic or micron filtration
•   Introduce daphnia to the tank

Water changes will reduce green water temporarily, but will not eliminate it.  Completely blocking  out all light for three days or more is very effective.  The use of a diatomic filter will remove the suspended algae.  If daphnia are available, they will quickly eat the microscopic algae, then in turn be eaten by the fish.

Note: Water aggregators that profess to clump suspended algae and remove it are not effective against green water.

•   Regular water changes
•   Regular aquarium cleaning
•   Use of UV Filter
•   Avoid direct sunlight on tank
•   Avoid overfeeding fish
•   Do not overstock the tank

As with any algae, keeping the tank clean and performing regular water changes is one of the best preventative measures. Prompt attention to sudden algae growth will prevent more serious problems



Credits by Kilian

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