Post by MADMIKE on Oct 19, 2006 7:51:37 GMT -5
There are two categories of algae of concern to aquarists: "good" and "bad". Good algae is present in small quantities, is indicative of good water quality and is easily kept in check by algae eating fish or simple removal during routine maintenance. This algae is a natural consequence of having a container of water with nutrients and a light source.
Bad algae is either an indicator of bad water quality or is a type of algae that tends to overtake the tank and ruin the aesthetics the aquarist is trying to achieve. The label of "bad" is entirely subjective. For example, one type of green, hair-like algae is considered a plague by some American aquarists, yet is cultivated by European aquarists as a valuable addition to most tanks, serving as a dietary supplement for the fish.
Algae Types
Blue-green, slime or smear algae
Grows rapidly in blue-green, slimy sheets. Spreads rapidly over almost everything and usually indicates poor water quality. However, blue-green algae can fix nitrogen and may be seen in aquariums with extremely low nitrates. Sometimes seen in small quantities between the substrate and aquarium sides. Will smother and kill plants.
This is actually cyanobacteria. It can be physically removed, but this is not a viable long term solution as the aquarium conditions are still favorable for it and it will return quickly. Treatment with 200 mg of erythromycin phosphate per 10 gallons of water will usually eliminate blue-green algae but some experts feel it may also have adverse effects on the biological filter bed. If erythromycin is used for treatment, ammonia and nitrite levels should be carefully monitored.
Brown algae
Forms in soft brown clumpy patches. In the freshwater aquarium, these are usually diatoms. Usually indicates a lack of light or an excess of silicates. Increased light levels will usually make it disappear. Easily removed by wiping the glass or siphon vacuuming the affected area.
Green water
Green unicellular algae will sometimes reproduce so rapidly that the water will turn green. This is commonly called an "algae bloom" and is usually caused by too much light like direct sunlight.
An algae bloom can be removed by filtering with micron cartridges or diatom filters. UV sterilizers can prevent the bloom in the first place. Green water is very useful in the raising of daphnia and brine shrimp.
Film algae
Grows on the aquarium glass and forms a thin haze. Easily removed by wiping the glass. Considered normal with the higher light levels needed for good plant growth.
Spot algae
Grows in thin, hard, circular, bright green spots, usually on the aquarium glass but also on plants under high light conditions. Considered normal for planted tanks. Must be mechanically removed. On acrylic aquariums, use a cloth pad or a gentle scouring pad like a cosmetic "Buff-Puff" and a lot of elbow grease. On glass tanks, scraping with a razor blade is most effective.
Fuzz algae
Grows mostly on plant leaves as separate, short (2-3mm) strands. Considered normal. It might be a less "virulent" form of "beard" algae. Easily controlled with algae eaters such as black mollies, Otocinclus, Peckoltia and siamese algae eaters.
Beard algae
Grows on plant leaves and is bright green. Individual strands have a very fine texture but it grows in thick patches and looks just like a green beard. It grows up to 4 cm. It cannot be removed mechanically. This does not indicate bad water quality but grows very fast and overtakes the tank, making it a "bad" alga. Can be eliminated with Simazine (Aquarium Pharmaceuticals "Algae-Destroyer").
Hair algae
Grows in bright green clumps in the gravel, around the base of plants like Echinodorus and around mechanical objects. It has a coarser texture than "beard algae". Beard algae will ripple in the water current, hair algae tends to form matted clumps. Individual strands can get to 5 cm or more. This is easy to remove mechanically by twirling a toothbrush in it. Can be troublesome if left unchecked. This is a popular food supplement for fish among European aquarists.
Thread algae
Grows in long, thin strands up to 30 cm or more. Tends toward a dull green color (hard to tell because it is so thin). Usually indicates an excess of iron (> 0.15 ppm). Easily removed with a toothbrush like hair algae.
Staghorn algae
Looks like individual strands of hair algae but tends to grow in single branching strands like a deer antler and is grey-green. Seems to grow mostly on tank equipment near the surface. Difficult to remove mechanically. Soak affected equipment in a 25% solution of household bleach and water to remove it.
Brush algae
This grows in feathery black tufts 2-3 mm long and tends to collect on slower growing leaves like Anubias, some Echinodorus and other wide leaf plants. Also tends to collect on mechanical equipment. This is actually a red alga in the genus Audouinella (other names: Acrochaetium, Rhodochorton, Chantransia).
It cannot easily be removed mechanically. Remove and discard the affected leaves. Equipment can be soaked in a 25% bleach solution, then scrubbed to remove the dead algae. Siamese Algae Eaters (Crossocheilus siamensis) are known to eat this algae and can keep it in check. A more drastic measure is treatment with copper.
Prophylactics for Algae
Algal spores are everywhere and will always be present in an aquarium unless drastic measures are taken. For fish only tanks, a properly set up ultraviolet sterilizer will kill algal spores in the water and prevent them from gaining a toehold.
For planted tanks, this is not a good solution since the UV light will also oxidize trace elements needed by the plants and will limit the plant's growth potential. Unfortunately, conditions that are good for growing plants are also good for growing algae. Fortunately, plants will usually out-compete algae for the available nutrients. However, if there is an imbalance of nutrients, algae will opportunistically use whatever is not used by the higher order plants. Different algae will utilize different nutrients, causing sporadic outbreaks of new algae types in apparently stable tanks when a temporary imbalance occurs.
An ounce of prevention is worth a pound of cure. To avoid introducing a new algae type to a planted tank with new plants, a simple bleach dip seems to work well. Mix 1 part bleach in 19 parts water and dip the new plant in it for 2 minutes. Immediately rinse the plant in running water, then immerse it water containing a chlorine remover to neutralize any remaining bleach. This will kill the algae and only temporarily slow down a healthy plant. Plants in poor condition may succumb to this treatment, but they probably would not have lasted anyway.
Bad algae is either an indicator of bad water quality or is a type of algae that tends to overtake the tank and ruin the aesthetics the aquarist is trying to achieve. The label of "bad" is entirely subjective. For example, one type of green, hair-like algae is considered a plague by some American aquarists, yet is cultivated by European aquarists as a valuable addition to most tanks, serving as a dietary supplement for the fish.
Algae Types
Blue-green, slime or smear algae
Grows rapidly in blue-green, slimy sheets. Spreads rapidly over almost everything and usually indicates poor water quality. However, blue-green algae can fix nitrogen and may be seen in aquariums with extremely low nitrates. Sometimes seen in small quantities between the substrate and aquarium sides. Will smother and kill plants.
This is actually cyanobacteria. It can be physically removed, but this is not a viable long term solution as the aquarium conditions are still favorable for it and it will return quickly. Treatment with 200 mg of erythromycin phosphate per 10 gallons of water will usually eliminate blue-green algae but some experts feel it may also have adverse effects on the biological filter bed. If erythromycin is used for treatment, ammonia and nitrite levels should be carefully monitored.
Brown algae
Forms in soft brown clumpy patches. In the freshwater aquarium, these are usually diatoms. Usually indicates a lack of light or an excess of silicates. Increased light levels will usually make it disappear. Easily removed by wiping the glass or siphon vacuuming the affected area.
Green water
Green unicellular algae will sometimes reproduce so rapidly that the water will turn green. This is commonly called an "algae bloom" and is usually caused by too much light like direct sunlight.
An algae bloom can be removed by filtering with micron cartridges or diatom filters. UV sterilizers can prevent the bloom in the first place. Green water is very useful in the raising of daphnia and brine shrimp.
Film algae
Grows on the aquarium glass and forms a thin haze. Easily removed by wiping the glass. Considered normal with the higher light levels needed for good plant growth.
Spot algae
Grows in thin, hard, circular, bright green spots, usually on the aquarium glass but also on plants under high light conditions. Considered normal for planted tanks. Must be mechanically removed. On acrylic aquariums, use a cloth pad or a gentle scouring pad like a cosmetic "Buff-Puff" and a lot of elbow grease. On glass tanks, scraping with a razor blade is most effective.
Fuzz algae
Grows mostly on plant leaves as separate, short (2-3mm) strands. Considered normal. It might be a less "virulent" form of "beard" algae. Easily controlled with algae eaters such as black mollies, Otocinclus, Peckoltia and siamese algae eaters.
Beard algae
Grows on plant leaves and is bright green. Individual strands have a very fine texture but it grows in thick patches and looks just like a green beard. It grows up to 4 cm. It cannot be removed mechanically. This does not indicate bad water quality but grows very fast and overtakes the tank, making it a "bad" alga. Can be eliminated with Simazine (Aquarium Pharmaceuticals "Algae-Destroyer").
Hair algae
Grows in bright green clumps in the gravel, around the base of plants like Echinodorus and around mechanical objects. It has a coarser texture than "beard algae". Beard algae will ripple in the water current, hair algae tends to form matted clumps. Individual strands can get to 5 cm or more. This is easy to remove mechanically by twirling a toothbrush in it. Can be troublesome if left unchecked. This is a popular food supplement for fish among European aquarists.
Thread algae
Grows in long, thin strands up to 30 cm or more. Tends toward a dull green color (hard to tell because it is so thin). Usually indicates an excess of iron (> 0.15 ppm). Easily removed with a toothbrush like hair algae.
Staghorn algae
Looks like individual strands of hair algae but tends to grow in single branching strands like a deer antler and is grey-green. Seems to grow mostly on tank equipment near the surface. Difficult to remove mechanically. Soak affected equipment in a 25% solution of household bleach and water to remove it.
Brush algae
This grows in feathery black tufts 2-3 mm long and tends to collect on slower growing leaves like Anubias, some Echinodorus and other wide leaf plants. Also tends to collect on mechanical equipment. This is actually a red alga in the genus Audouinella (other names: Acrochaetium, Rhodochorton, Chantransia).
It cannot easily be removed mechanically. Remove and discard the affected leaves. Equipment can be soaked in a 25% bleach solution, then scrubbed to remove the dead algae. Siamese Algae Eaters (Crossocheilus siamensis) are known to eat this algae and can keep it in check. A more drastic measure is treatment with copper.
Prophylactics for Algae
Algal spores are everywhere and will always be present in an aquarium unless drastic measures are taken. For fish only tanks, a properly set up ultraviolet sterilizer will kill algal spores in the water and prevent them from gaining a toehold.
For planted tanks, this is not a good solution since the UV light will also oxidize trace elements needed by the plants and will limit the plant's growth potential. Unfortunately, conditions that are good for growing plants are also good for growing algae. Fortunately, plants will usually out-compete algae for the available nutrients. However, if there is an imbalance of nutrients, algae will opportunistically use whatever is not used by the higher order plants. Different algae will utilize different nutrients, causing sporadic outbreaks of new algae types in apparently stable tanks when a temporary imbalance occurs.
An ounce of prevention is worth a pound of cure. To avoid introducing a new algae type to a planted tank with new plants, a simple bleach dip seems to work well. Mix 1 part bleach in 19 parts water and dip the new plant in it for 2 minutes. Immediately rinse the plant in running water, then immerse it water containing a chlorine remover to neutralize any remaining bleach. This will kill the algae and only temporarily slow down a healthy plant. Plants in poor condition may succumb to this treatment, but they probably would not have lasted anyway.